diff --git a/extension-command.php b/extension-command.php
index 18b87efd..3cc65c80 100644
--- a/extension-command.php
+++ b/extension-command.php
@@ -22,3 +22,33 @@
 WP_CLI::add_command( 'theme', 'Theme_Command' );
 WP_CLI::add_command( 'theme auto-updates', 'Theme_AutoUpdates_Command', $wpcli_extension_requires_wp_5_5 );
 WP_CLI::add_command( 'theme mod', 'Theme_Mod_Command' );
+
+// In admin context, WordPress hooks wp_update_plugins/wp_update_themes to
+// various actions, causing update checks to run even when --skip-update-check is passed.
+
+WP_CLI::add_hook(
+	'before_wp_load',
+	static function () {
+		if ( ! \WP_CLI\Utils\get_flag_value( WP_CLI::get_runner()->assoc_args, 'skip-update-check' ) ) {
+			return;
+		}
+
+		WP_CLI::add_wp_hook(
+			'wp_loaded',
+			static function () {
+				remove_action( 'load-plugins.php', 'wp_update_plugins' );
+				remove_action( 'load-update.php', 'wp_update_plugins' );
+				remove_action( 'load-update-core.php', 'wp_update_plugins' );
+				remove_action( 'admin_init', '_maybe_update_plugins' );
+				remove_action( 'wp_update_plugins', 'wp_update_plugins' );
+
+				remove_action( 'load-themes.php', 'wp_update_themes' );
+				remove_action( 'load-update.php', 'wp_update_themes' );
+				remove_action( 'load-update-core.php', 'wp_update_themes' );
+				remove_action( 'admin_init', '_maybe_update_themes' );
+				remove_action( 'wp_update_themes', 'wp_update_themes' );
+			},
+			PHP_INT_MIN
+		);
+	}
+);
diff --git a/features/plugin-auto-updates-disable.feature b/features/plugin-auto-updates-disable.feature
index af988a46..57eb1c5b 100644
--- a/features/plugin-auto-updates-disable.feature
+++ b/features/plugin-auto-updates-disable.feature
@@ -2,7 +2,7 @@ Feature: Disable auto-updates for WordPress plugins
 
   Background:
     Given a WP install
-    And I run `wp plugin install duplicate-post https://github.com/wp-cli/sample-plugin/archive/refs/heads/master.zip --ignore-requirements`
+    And I run `wp plugin install debug-bar https://github.com/wp-cli/sample-plugin/archive/refs/heads/master.zip --ignore-requirements`
     And I run `wp plugin auto-updates enable --all`
 
   @require-wp-5.5
@@ -25,7 +25,7 @@ Feature: Disable auto-updates for WordPress plugins
 
   @require-wp-5.5
   Scenario: Disable auto-updates for multiple plugins
-    When I run `wp plugin auto-updates disable sample-plugin duplicate-post`
+    When I run `wp plugin auto-updates disable sample-plugin debug-bar`
     Then STDOUT should be:
       """
       Success: Disabled 2 of 2 plugin auto-updates.
@@ -73,7 +73,7 @@ Feature: Disable auto-updates for WordPress plugins
   @require-wp-5.5
   Scenario: Filter when disabling auto-updates for already disabled selection of plugins
     When I run `wp plugin auto-updates disable sample-plugin`
-    And I run `wp plugin auto-updates disable sample-plugin duplicate-post --enabled-only`
+    And I run `wp plugin auto-updates disable sample-plugin debug-bar --enabled-only`
     Then STDOUT should be:
       """
       Success: Disabled 1 of 1 plugin auto-updates.
diff --git a/features/plugin-auto-updates-enable.feature b/features/plugin-auto-updates-enable.feature
index 73de4ba5..19b6384a 100644
--- a/features/plugin-auto-updates-enable.feature
+++ b/features/plugin-auto-updates-enable.feature
@@ -2,7 +2,7 @@ Feature: Enable auto-updates for WordPress plugins
 
   Background:
     Given a WP install
-    And I run `wp plugin install duplicate-post https://github.com/wp-cli/sample-plugin/archive/refs/heads/master.zip --ignore-requirements`
+    And I run `wp plugin install debug-bar https://github.com/wp-cli/sample-plugin/archive/refs/heads/master.zip --ignore-requirements`
 
   @require-wp-5.5
   Scenario: Show an error if required params are missing
@@ -24,7 +24,7 @@ Feature: Enable auto-updates for WordPress plugins
 
   @require-wp-5.5
   Scenario: Enable auto-updates for multiple plugins
-    When I run `wp plugin auto-updates enable sample-plugin duplicate-post`
+    When I run `wp plugin auto-updates enable sample-plugin debug-bar`
     Then STDOUT should be:
       """
       Success: Enabled 2 of 2 plugin auto-updates.
@@ -72,7 +72,7 @@ Feature: Enable auto-updates for WordPress plugins
   @require-wp-5.5
   Scenario: Filter when enabling auto-updates for already enabled selection of plugins
     When I run `wp plugin auto-updates enable sample-plugin`
-    And I run `wp plugin auto-updates enable sample-plugin duplicate-post --disabled-only`
+    And I run `wp plugin auto-updates enable sample-plugin debug-bar --disabled-only`
     Then STDOUT should be:
       """
       Success: Enabled 1 of 1 plugin auto-updates.
diff --git a/features/plugin-auto-updates-status.feature b/features/plugin-auto-updates-status.feature
index d4a7c424..4bda9736 100644
--- a/features/plugin-auto-updates-status.feature
+++ b/features/plugin-auto-updates-status.feature
@@ -2,7 +2,7 @@ Feature: Show the status of auto-updates for WordPress plugins
 
   Background:
     Given a WP install
-    And I run `wp plugin install duplicate-post https://github.com/wp-cli/sample-plugin/archive/refs/heads/master.zip --ignore-requirements`
+    And I run `wp plugin install debug-bar https://github.com/wp-cli/sample-plugin/archive/refs/heads/master.zip --ignore-requirements`
 
   @require-wp-5.5
   Scenario: Show an error if required params are missing
@@ -23,10 +23,10 @@ Feature: Show the status of auto-updates for WordPress plugins
 
   @require-wp-5.5
   Scenario: Show the status of auto-updates multiple plugins
-    When I run `wp plugin auto-updates status duplicate-post sample-plugin`
+    When I run `wp plugin auto-updates status debug-bar sample-plugin`
     Then STDOUT should be a table containing rows:
       | name           | status   |
-      | duplicate-post | disabled |
+      | debug-bar | disabled |
       | sample-plugin          | disabled |
     And the return code should be 0
 
@@ -36,7 +36,7 @@ Feature: Show the status of auto-updates for WordPress plugins
     Then STDOUT should be a table containing rows:
       | name           | status   |
       | akismet        | disabled |
-      | duplicate-post | disabled |
+      | debug-bar | disabled |
       | sample-plugin          | disabled |
     And the return code should be 0
 
@@ -45,7 +45,7 @@ Feature: Show the status of auto-updates for WordPress plugins
     Then STDOUT should be a table containing rows:
       | name           | status   |
       | akismet        | enabled  |
-      | duplicate-post | enabled  |
+      | debug-bar | enabled  |
       | sample-plugin          | enabled  |
     And the return code should be 0
 
@@ -57,7 +57,7 @@ Feature: Show the status of auto-updates for WordPress plugins
     Then STDOUT should be a table containing rows:
       | name           | status   |
       | akismet        | disabled |
-      | duplicate-post | disabled |
+      | debug-bar | disabled |
       | sample-plugin          | enabled  |
     And the return code should be 0
 
@@ -71,7 +71,7 @@ Feature: Show the status of auto-updates for WordPress plugins
     Then STDOUT should be a table containing rows:
       | name           | status   |
       | akismet        | disabled |
-      | duplicate-post | disabled |
+      | debug-bar | disabled |
     And the return code should be 0
 
     When I try `wp plugin auto-updates status --all --enabled-only --disabled-only`
@@ -92,7 +92,7 @@ Feature: Show the status of auto-updates for WordPress plugins
       """
     And STDOUT should contain:
       """
-      duplicate-post
+      debug-bar
       """
 
     When I run `wp plugin auto-updates status sample-plugin --field=status`
@@ -114,7 +114,7 @@ Feature: Show the status of auto-updates for WordPress plugins
       """
     And STDOUT should contain:
       """
-      {"name":"duplicate-post","status":"disabled"}
+      {"name":"debug-bar","status":"disabled"}
       """
 
     When I run `wp plugin auto-updates status --all --format=csv`
@@ -128,7 +128,7 @@ Feature: Show the status of auto-updates for WordPress plugins
       """
     And STDOUT should contain:
       """
-      duplicate-post,disabled
+      debug-bar,disabled
       """
 
   @require-wp-5.5
diff --git a/features/plugin-dependencies.feature b/features/plugin-dependencies.feature
index 96c0f41b..0faae774 100644
--- a/features/plugin-dependencies.feature
+++ b/features/plugin-dependencies.feature
@@ -61,7 +61,7 @@ Feature: Plugin dependencies support
       <?php
       /**
        * Plugin Name: Test Plugin
-       * Requires Plugins: duplicate-post, debug-bar
+       * Requires Plugins: debug-bar, disable-embeds
        */
       """
 
@@ -75,13 +75,13 @@ Feature: Plugin dependencies support
       Success:
       """
 
-    When I run `wp plugin list --name=duplicate-post --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       inactive
       """
 
-    When I run `wp plugin list --name=debug-bar --field=status`
+    When I run `wp plugin list --name=disable-embeds --field=status`
     Then STDOUT should be:
       """
       inactive
@@ -119,7 +119,8 @@ Feature: Plugin dependencies support
       Warning: akismet: Plugin already installed.
       """
 
-    When I run `wp plugin list --fields=name,status --format=csv`
+    # Expecting a warning for BuddyPress attempting a redirect upon activation.
+    When I try `wp plugin list --fields=name,status --format=csv`
     Then STDOUT should contain:
       """
       buddypress,active
diff --git a/features/plugin-install.feature b/features/plugin-install.feature
index 6fc3b538..c748546e 100644
--- a/features/plugin-install.feature
+++ b/features/plugin-install.feature
@@ -323,6 +323,10 @@ Feature: Install WordPress plugins
       """
       Warning: Plugin already installed.
       """
+    And STDERR should not contain:
+      """
+      plugin could not be found
+      """
     And STDOUT should contain:
       """
       Success: Plugin already installed.
@@ -371,14 +375,14 @@ Feature: Install WordPress plugins
   Scenario: Install plugin using WordPress.org directory URL
     Given a WP install
 
-    When I run `wp plugin install https://wordpress.org/plugins/hello-dolly/`
+    When I run `wp plugin install https://wordpress.org/plugins/debug-bar/`
     Then STDOUT should contain:
       """
-      Detected WordPress.org plugins directory URL, using slug: hello-dolly
+      Detected WordPress.org plugins directory URL, using slug: debug-bar
       """
     And the return code should be 0
 
-    When I run `wp plugin list --name=hello-dolly --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       inactive
@@ -387,14 +391,14 @@ Feature: Install WordPress plugins
   Scenario: Install and activate plugin using WordPress.org directory URL
     Given a WP install
 
-    When I run `wp plugin install https://wordpress.org/plugins/hello-dolly/ --activate`
+    When I run `wp plugin install https://wordpress.org/plugins/debug-bar/ --activate`
     Then STDOUT should contain:
       """
-      Detected WordPress.org plugins directory URL, using slug: hello-dolly
+      Detected WordPress.org plugins directory URL, using slug: debug-bar
       """
     And the return code should be 0
 
-    When I run `wp plugin list --name=hello-dolly --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       active
@@ -403,35 +407,35 @@ Feature: Install WordPress plugins
   Scenario: Install with --activate on already-active plugin should keep it activated
     Given a WP install
 
-    When I run `wp plugin install hello-dolly --activate`
+    When I run `wp plugin install debug-bar --activate`
     Then STDOUT should contain:
       """
-      Plugin 'hello-dolly' activated.
+      Plugin 'debug-bar' activated.
       """
     And the return code should be 0
 
-    When I run `wp plugin list --name=hello-dolly --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       active
       """
 
-    When I try `wp plugin install hello-dolly --activate`
+    When I try `wp plugin install debug-bar --activate`
     Then STDERR should contain:
       """
-      Warning: hello-dolly: Plugin already installed.
+      Warning: debug-bar: Plugin already installed.
       """
     And STDOUT should contain:
       """
-      Activating 'hello-dolly'...
+      Activating 'debug-bar'...
       """
     And STDOUT should contain:
       """
-      Plugin 'hello-dolly' activated.
+      Plugin 'debug-bar' activated.
       """
     And the return code should be 0
 
-    When I run `wp plugin list --name=hello-dolly --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       active
@@ -440,35 +444,35 @@ Feature: Install WordPress plugins
   Scenario: Install with --activate-network on already-network-active plugin should keep it activated
     Given a WP multisite install
 
-    When I run `wp plugin install hello-dolly --activate-network`
+    When I run `wp plugin install debug-bar --activate-network`
     Then STDOUT should contain:
       """
-      Plugin 'hello-dolly' network activated.
+      Plugin 'debug-bar' network activated.
       """
     And the return code should be 0
 
-    When I run `wp plugin list --name=hello-dolly --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       active-network
       """
 
-    When I try `wp plugin install hello-dolly --activate-network`
+    When I try `wp plugin install debug-bar --activate-network`
     Then STDERR should contain:
       """
-      Warning: hello-dolly: Plugin already installed.
+      Warning: debug-bar: Plugin already installed.
       """
     And STDOUT should contain:
       """
-      Network-activating 'hello-dolly'...
+      Network-activating 'debug-bar'...
       """
     And STDOUT should contain:
       """
-      Plugin 'hello-dolly' network activated.
+      Plugin 'debug-bar' network activated.
       """
     And the return code should be 0
 
-    When I run `wp plugin list --name=hello-dolly --field=status`
+    When I run `wp plugin list --name=debug-bar --field=status`
     Then STDOUT should be:
       """
       active-network
diff --git a/features/plugin-search.feature b/features/plugin-search.feature
index ab5e5bbc..8a560a4f 100644
--- a/features/plugin-search.feature
+++ b/features/plugin-search.feature
@@ -22,7 +22,7 @@ Feature: Search WordPress.org plugins
   Scenario: Search for plugins with url field
     Given a WP install
 
-    When I run `wp plugin search gutenberg --fields=slug,url --format=csv`
+    When I run `wp plugin search gutenberg --fields=slug,url --format=csv --per-page=20`
     Then STDOUT should contain:
       """
       gutenberg,https://wordpress.org/plugins/gutenberg/
diff --git a/features/plugin.feature b/features/plugin.feature
index cacaa996..90fbae31 100644
--- a/features/plugin.feature
+++ b/features/plugin.feature
@@ -428,8 +428,12 @@ Feature: Manage WordPress plugins
       Success: Transient deleted.
       """
 
-    When I run `wp plugin list --fields=name,status,update --status=inactive --skip-update-check`
-    Then STDOUT should be a table containing rows:
+    When I run `wp plugin list --fields=name,status,update --status=inactive --skip-update-check --debug=http`
+    Then STDERR should not contain:
+      """
+      HTTP POST request to https://api.wordpress.org/plugins/update-check
+      """
+    And STDOUT should be a table containing rows:
       | name               | status   | update   |
       | wordpress-importer | inactive | none     |
 
diff --git a/features/theme.feature b/features/theme.feature
index 259f1f68..591a0d87 100644
--- a/features/theme.feature
+++ b/features/theme.feature
@@ -228,8 +228,12 @@ Feature: Manage WordPress themes
       Success: Transient deleted.
       """
 
-    When I run `wp theme list --fields=name,status,update --skip-update-check`
-    Then STDOUT should be a table containing rows:
+    When I run `wp theme list --fields=name,status,update --skip-update-check --debug=http`
+    Then STDERR should not contain:
+      """
+      HTTP POST request to https://api.wordpress.org/themes/update-check
+      """
+    And STDOUT should be a table containing rows:
       | name      | status   | update |
       | astra     | inactive | none   |
 
diff --git a/src/WP_CLI/CommandWithUpgrade.php b/src/WP_CLI/CommandWithUpgrade.php
index d1623c97..e7d64d40 100755
--- a/src/WP_CLI/CommandWithUpgrade.php
+++ b/src/WP_CLI/CommandWithUpgrade.php
@@ -254,7 +254,11 @@ public function install( $args, $assoc_args ) {
 				} else {
 					// $result is WP_Error here
 					WP_CLI::warning( $result->get_error_message() );
-					if ( 'already_installed' !== $result->get_error_code() ) {
+					if ( 'already_installed' === $result->get_error_code() ) {
+						if ( $result->get_error_data( 'slug' ) ) {
+							$slug = $result->get_error_data( 'slug' );
+						}
+					} else {
 						++$errors;
 					}
 				}
@@ -338,6 +342,11 @@ public function install( $args, $assoc_args ) {
 				}
 			}
 
+			// Only plugins cache really exists.
+			if ( 'plugin' === $this->item_type ) {
+				wp_cache_delete( 'plugins', 'plugins' );
+			}
+
 			// Check extension is available or not.
 			$extension = $this->fetcher->get_many( array( $slug ) );
 
@@ -411,7 +420,10 @@ protected function install_from_php_file( $url, $assoc_args ) {
 
 		// Check if plugin is already installed before downloading.
 		if ( file_exists( $dest_path ) && ! Utils\get_flag_value( $assoc_args, 'force' ) ) {
-			return new WP_Error( 'already_installed', 'Plugin already installed.' );
+			$error = new WP_Error( 'already_installed', 'Plugin already installed.' );
+			// An easy way to provide the slug of the installed plugin.
+			$error->add_data( $dest_filename, 'slug' );
+			return $error;
 		}
 
 		// Ensure plugin directory exists.