diff --git a/src/Rules/IssetCheck.php b/src/Rules/IssetCheck.php
index 2e1adcf1c68..f8f7767d7aa 100644
--- a/src/Rules/IssetCheck.php
+++ b/src/Rules/IssetCheck.php
@@ -182,15 +182,10 @@ static function (Type $type) use ($typeMessageCallback): ?string {
 				}
 
 				if (!$scope->hasExpressionType($expr)->yes()) {
-					if ($expr instanceof Node\Expr\PropertyFetch) {
-						return $this->checkUndefined($expr->var, $scope, $operatorDescription, $identifier);
-					}
-
-					if ($expr->class instanceof Expr) {
-						return $this->checkUndefined($expr->class, $scope, $operatorDescription, $identifier);
+					$nativeReflection = $propertyReflection->getNativeReflection();
+					if ($nativeReflection !== null && !$nativeReflection->getNativeReflection()->hasDefaultValue()) {
+						return null;
 					}
-
-					return null;
 				}
 			}
 
diff --git a/src/Type/Php/ArrayFindFunctionReturnTypeExtension.php b/src/Type/Php/ArrayFindFunctionReturnTypeExtension.php
index 93655fa68c7..091433436c3 100644
--- a/src/Type/Php/ArrayFindFunctionReturnTypeExtension.php
+++ b/src/Type/Php/ArrayFindFunctionReturnTypeExtension.php
@@ -37,8 +37,8 @@ public function getTypeFromFunctionCall(FunctionReflection $functionReflection,
 			return null;
 		}
 
-		$arrayArg = $args[0]->value ?? null;
-		$callbackArg = $args[1]->value ?? null;
+		$arrayArg = $args[0]->value;
+		$callbackArg = $args[1]->value;
 
 		$resultTypes = $this->arrayFilterFunctionReturnTypeHelper->getType($scope, $arrayArg, $callbackArg, null);
 		$resultType = TypeCombinator::union(...array_map(static fn ($type) => $type->getIterableValueType(), $resultTypes->getArrays()));
diff --git a/tests/PHPStan/Rules/Variables/EmptyRuleTest.php b/tests/PHPStan/Rules/Variables/EmptyRuleTest.php
index 873c89fb869..d14d6c24d84 100644
--- a/tests/PHPStan/Rules/Variables/EmptyRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/EmptyRuleTest.php
@@ -223,6 +223,18 @@ public function testBug7806(): void
 		$this->analyse([__DIR__ . '/data/bug-7806.php'], []);
 	}
 
+	public function testBug14393(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14393.php'], [
+			[
+				'Variable $undefinedVar in empty() is never defined.',
+				166,
+			],
+		]);
+	}
+
 	#[RequiresPhp('>= 8.0')]
 	public function testIssetAfterRememberedConstructor(): void
 	{
diff --git a/tests/PHPStan/Rules/Variables/IssetRuleTest.php b/tests/PHPStan/Rules/Variables/IssetRuleTest.php
index 11f2b39f1fd..fd841e49b16 100644
--- a/tests/PHPStan/Rules/Variables/IssetRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/IssetRuleTest.php
@@ -202,13 +202,10 @@ public function testNativePropertyTypes(): void
 	{
 		$this->treatPhpDocTypesAsCertain = true;
 		$this->analyse([__DIR__ . '/data/isset-native-property-types.php'], [
-			/*[
-				// no way to achieve this with current PHP Reflection API
-				// There's ReflectionClass::getDefaultProperties()
-				// but it cannot differentiate between `public int $foo` and `public int $foo = null`;
+			[
 				'Property IssetNativePropertyTypes\Foo::$hasDefaultValue (int) in isset() is not nullable.',
 				17,
-			],*/
+			],
 			[
 				'Property IssetNativePropertyTypes\Foo::$isAssignedBefore (int) in isset() is not nullable.',
 				20,
@@ -529,4 +526,40 @@ public function testBug9503(): void
 		$this->analyse([__DIR__ . '/data/bug-9503.php'], []);
 	}
 
+	public function testBug14393(): void
+	{
+		$this->treatPhpDocTypesAsCertain = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14393.php'], [
+			[
+				'Property Bug14393\MyClass::$i (int) in isset() is not nullable.',
+				12,
+			],
+			[
+				'Property Bug14393\MyClassPhpDoc::$i (int) in isset() is not nullable.',
+				37,
+			],
+			[
+				'Property Bug14393\MyClass::$i (int) in isset() is not nullable.',
+				81,
+			],
+			[
+				'Property Bug14393\MyClassPhpDoc::$i (int) in isset() is not nullable.',
+				93,
+			],
+			[
+				'Static property Bug14393\MyClassStatic::$i (int) in isset() is not nullable.',
+				121,
+			],
+			[
+				'Static property Bug14393\MyClassStatic::$i (int) in isset() is not nullable.',
+				151,
+			],
+			[
+				'Variable $undefinedVar in isset() is never defined.',
+				165,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php b/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
index 32cfa69d97b..d6a06d85810 100644
--- a/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php
@@ -377,4 +377,48 @@ public function testBug13921(): void
 		]);
 	}
 
+	public function testBug4846(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-4846.php'], [
+			[
+				'Property Bug4846\Foo::$alwaysString (string) on left side of ?? is not nullable.',
+				13,
+			],
+		]);
+	}
+
+	public function testBug14393(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-14393.php'], [
+			[
+				'Property Bug14393\MyClass::$i (int) on left side of ?? is not nullable.',
+				11,
+			],
+			[
+				'Property Bug14393\MyClassPhpDoc::$i (int) on left side of ?? is not nullable.',
+				36,
+			],
+			[
+				'Property Bug14393\MyClass::$i (int) on left side of ?? is not nullable.',
+				80,
+			],
+			[
+				'Property Bug14393\MyClassPhpDoc::$i (int) on left side of ?? is not nullable.',
+				92,
+			],
+			[
+				'Static property Bug14393\MyClassStatic::$i (int) on left side of ?? is not nullable.',
+				120,
+			],
+			[
+				'Static property Bug14393\MyClassStatic::$i (int) on left side of ?? is not nullable.',
+				150,
+			],
+			[
+				'Variable $undefinedVar on left side of ?? is never defined.',
+				164,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Variables/data/bug-14393.php b/tests/PHPStan/Rules/Variables/data/bug-14393.php
new file mode 100644
index 00000000000..c03ca903c33
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-14393.php
@@ -0,0 +1,167 @@
+<?php declare(strict_types = 1);
+
+namespace Bug14393;
+
+class MyClass
+{
+	public int $i = 10;
+
+	public function doFoo(): void
+	{
+		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
+		var_dump(empty($this->i));
+	}
+}
+
+class MyClassUninitialized
+{
+	public int $i;
+
+	public function doFoo(): void
+	{
+		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
+		var_dump(empty($this->i));
+	}
+}
+
+class MyClassPhpDoc
+{
+	/** @var int */
+	public $i;
+
+	public function doFoo(): void
+	{
+		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
+		var_dump(empty($this->i));
+	}
+}
+
+class MyClassNullable
+{
+	public ?int $i;
+
+	public function doFoo(): void
+	{
+		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
+		var_dump(empty($this->i));
+	}
+}
+
+class MyClassNullableWithDefault
+{
+	public ?int $i = 10;
+
+	public function doFoo(): void
+	{
+		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
+		var_dump(empty($this->i));
+	}
+}
+
+class MyClassNullableWithNullDefault
+{
+	public ?int $i = null;
+
+	public function doFoo(): void
+	{
+		var_dump($this->i ?? -1);
+		var_dump(isset($this->i));
+		var_dump(empty($this->i));
+	}
+}
+
+$o = new MyClass();
+
+var_dump($o->i ?? -1);
+var_dump(isset($o->i));
+var_dump(empty($o->i));
+
+$o2 = new MyClassUninitialized();
+
+var_dump($o2->i ?? -1);
+var_dump(isset($o2->i));
+var_dump(empty($o2->i));
+
+$o3 = new MyClassPhpDoc();
+
+var_dump($o3->i ?? -1);
+var_dump(isset($o3->i));
+var_dump(empty($o3->i));
+
+$o4 = new MyClassNullable();
+
+var_dump($o4->i ?? -1);
+var_dump(isset($o4->i));
+var_dump(empty($o4->i));
+
+$o5 = new MyClassNullableWithDefault();
+
+var_dump($o5->i ?? -1);
+var_dump(isset($o5->i));
+var_dump(empty($o5->i));
+
+$o6 = new MyClassNullableWithNullDefault();
+
+var_dump($o6->i ?? -1);
+var_dump(isset($o6->i));
+var_dump(empty($o6->i));
+
+class MyClassStatic
+{
+	public static int $i = 10;
+
+	public function doFoo(): void
+	{
+		var_dump(self::$i ?? -1);
+		var_dump(isset(self::$i));
+		var_dump(empty(self::$i));
+	}
+}
+
+class MyClassStaticUninitialized
+{
+	public static int $i;
+
+	public function doFoo(): void
+	{
+		var_dump(self::$i ?? -1);
+		var_dump(isset(self::$i));
+		var_dump(empty(self::$i));
+	}
+}
+
+class MyClassStaticNullable
+{
+	public static ?int $i = null;
+
+	public function doFoo(): void
+	{
+		var_dump(self::$i ?? -1);
+		var_dump(isset(self::$i));
+		var_dump(empty(self::$i));
+	}
+}
+
+var_dump(MyClassStatic::$i ?? -1);
+var_dump(isset(MyClassStatic::$i));
+var_dump(empty(MyClassStatic::$i));
+
+var_dump(MyClassStaticUninitialized::$i ?? -1);
+var_dump(isset(MyClassStaticUninitialized::$i));
+var_dump(empty(MyClassStaticUninitialized::$i));
+
+var_dump(MyClassStaticNullable::$i ?? -1);
+var_dump(isset(MyClassStaticNullable::$i));
+var_dump(empty(MyClassStaticNullable::$i));
+
+// Test undefined variable with native-typed property access
+function testUndefinedVar(): void {
+	var_dump($undefinedVar->i ?? -1);
+	var_dump(isset($undefinedVar->i));
+	var_dump(empty($undefinedVar->i));
+}
diff --git a/tests/PHPStan/Rules/Variables/data/bug-4846.php b/tests/PHPStan/Rules/Variables/data/bug-4846.php
new file mode 100644
index 00000000000..a6fbb2e660a
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-4846.php
@@ -0,0 +1,16 @@
+<?php declare(strict_types = 1);
+
+namespace Bug4846;
+
+class Foo
+{
+	public string $alwaysString = '';
+
+	public ?string $nullableString = null;
+}
+
+function (Foo $foo): void {
+	echo $foo->alwaysString ?? 'string';
+
+	echo $foo->nullableString ?? 'string';
+};