[Problem/Bug]: WebView2 browser print preview printer dropdown cannot be selected with mouse in Win32 embedded app

[luckytux]

What happened?

Description

In a Windows desktop app hosting WebView2, the browser print preview UI opens and displays the document preview correctly, but the printer dropdown cannot be reliably selected with the mouse.

Keyboard navigation works: I can use arrow keys to move through printers/options, but mouse clicks on dropdown options do not select the printer.

This blocks page-range printing workflows because the browser print preview is the only WebView2 print UI that shows page previews/page counts. The system print dialog is usable with the mouse, but it shows “No preview available,” so users cannot determine which pages to print.

Environment

• Windows 10 Home, version 2009, build 22631
• WebView2 Runtime 148.0.3967.70
• Flutter Windows desktop app
• Flutter 3.41.9 stable
• Dart 3.11.5
• webview_windows 0.4.0
• Win32/Flutter desktop app hosting WebView2 via a composition-backed WebView

Repro Steps

1. Render an HTML report inside an embedded WebView2 control.
2. Trigger browser print preview using either window.print() or ICoreWebView2_16::ShowPrintUI(COREWEBVIEW2_PRINT_DIALOG_KIND_BROWSER).
3. Open the printer dropdown in the print preview panel.
4. Try selecting a different printer using the mouse.

Expected Result

Printer dropdown items should be selectable with the mouse, same as in Edge/Chrome browser print preview.

Actual Result

The print preview opens and displays the document preview, but printer dropdown mouse selection does not work reliably. Keyboard arrow selection works.

Additional Findings

Using ICoreWebView2_16::ShowPrintUI(COREWEBVIEW2_PRINT_DIALOG_KIND_SYSTEM) opens the native/system print dialog and mouse selection works, but the dialog shows “No preview available.”

This is not sufficient for page-range workflows because users need preview/page count information before choosing pages.

We also attempted using WebView2 PrintToPdf from the embedded WebView as a workaround for a custom in-app preview, but that caused the app/WebView flow to stall in this composition-backed Flutter Windows setup.

Impact

Users need to print only selected pages from multi-page generated reports. The browser print preview provides the necessary preview/page context, but the broken mouse interaction makes it unreliable for normal users. The system dialog is stable, but lacks preview.

Importance

Important. My app's user experience is significantly compromised.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

148.0.3967.70

SDK Version

1.0.1210.39

Framework

Win32

Operating System

Windows 10

OS Version

22631.6199

Repro steps

1. Render an HTML report inside an embedded WebView2 control.
2. Trigger browser print preview using either window.print() or ICoreWebView2_16::ShowPrintUI(COREWEBVIEW2_PRINT_DIALOG_KIND_BROWSER).
3. Open the printer dropdown in the print preview panel.
4. Try selecting a different printer using the mouse.

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

No, this never worked

Last working version (if regression)

No response