Blank window appears during initialization of first WebView2

[nirdil]

What happened?

In a UWP app, when initializing the first off-screen WebView2, a blank window briefly appears for a few seconds before disappearing. I couldn’t reproduce this issue in a smaller sample project, so the conditions leading to this behavior are unclear. It seems to be a relatively recent bug introduced in the production Edge channel.

Additionally, this issue does not occur in the Edge Dev channel, which suggests it has been resolved in a later version. I’m unsure if this is a documented bug.

Can anyone confirm which version includes this fix and when it will be available in the production channel?

Importance

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

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

129.0.2792.52

SDK Version

1.0.2839

Framework

WinUI2/UWP

Operating System

Windows 10

OS Version

10.0.19045

Repro steps

Not reproducible on a small sample project

Repros in Edge Browser

No, issue does not reproduce in the corresponding Edge version

Regression

Regression in newer Runtime

Last working version (if regression)

No response

AB#54137238