[Windows] WebView Regression from NET9 to NET10

[Grzegorz1223]

Description

.NET10 WebViews are not dispalying correctly if we instance more than 1 at the same time. This was working correctly with .NET9

Steps to Reproduce

1. Clone the provided reproduction project
2. Compile it and start on windows
3. It will automatically open a HybridWebView in the Main window and an additional Window with a WebView
4. The additional Window will be blank, instead of showing the google.com page.
5. Here is a link to the same repro project but with NET9 where you can see the expected behavior
   https://github.com/Grzegorz1223/WebViewBugReproNET9

.NET10

.NET9

Link to public reproduction project repository

https://github.com/Grzegorz1223/WebViewBugReproNET10

Version with bug

10.0.50

Is this a regression from previous behavior?

Yes, this used to work in .NET MAUI

Last version that worked well

9.0.120 SR12

Affected platforms

Windows

Affected platform versions

No response

Did you find any workaround?

Just to rollback to NET9

Relevant log output

[NafeelaNazhir]

This issue has been validated in Visual Studio 18.4.0 with .NET MAUI versions 9.0.120, .NET 10 Preview 1, Preview 6, Preview 7, 10.0.0, and 10.0.50. It is reproducible on the Windows platform starting from .NET 10 Preview 7 and is not reproducible in versions prior to Preview 7.

• 10.0.50

• Preview6

[Grzegorz1223]

I think the regression comes from this change here:

https://github.com/dotnet/maui/pull/31027/changes#diff-9adaedb7571e93283664d8e3db8d34930d748bbe1207eb004f53e25e08eaaaeaL268

I think we should check the await webView.EnsureCoreWebView2Async(env, options);

this might be as well related:
#34413