Authentification error

What happened?

Hello,
I want to access a webserver inside a company network. The frontend is also inside the company network.
The webserver provides two websites, one for normal use and a test website.
The access to both websites is possible with MS Edge without any uppopping authentification windows.
In fact, for both website the windows authentification ist used.

When I access the normal website by webview2, everything works as expected.
But when I try to access the test website, there is allways an identification necessary.

Any ideas what causes this strange behaviour?

Manfred

Importance

Moderate. My app's user experience is affected, but still usable.

Runtime Channel

Stable release (WebView2 Runtime)

Runtime Version

latest

SDK Version

No response

Framework

Winforms

Operating System

Windows 11

OS Version

latest

Repro steps

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

No repository file, test, SDK version, or reproducible steps are provided. Start by reviewing the WinForms WebView2 authentication behavior against the two internal websites and the corresponding Edge behavior, then gather enough details to reproduce the difference. Done means identifying the cause and documenting or fixing the differing authentication behavior.