AppInstance.UnregisterKey() causes a failfast crash when called on a different thread than FindOrRegisterForKey(...) was called from

[contextfree]

Describe the bug

When I call AppInstance.UnregisterKey() from a different thread than FindOrRegisterForKey(...) was called from, for me it consistently immediately crashes the process with a 0xc0000409 code. It seems to happen when trying to reset a mutex, m_keyCreationMutexLock, inside UnregisterKey().

If this is intended/expected behavior, it should at least be called out in the documentation for FindOrRegisterForKey and UnregisterKey. This was very frustrating to debug.

Steps to reproduce the bug

Minimal reproduction:
`

        AppInstance.FindOrRegisterForKey("key");
        Thread.Sleep(3000);
        new Thread(() =>
        {
            AppInstance.GetCurrent().UnregisterKey();
        }).Start();`

Expected behavior

The key will be registered and unregistered, without crashing the process.

Screenshots

No response

NuGet package version

2.0.1

Packaging type

Packaged (MSIX)

Windows version

Windows 11 version 24H2 (26100, June 2025 Update)

IDE

Other

Additional context

No response

[castorix]

Yes, if i trace on Windows 10 22H2, it calls ReleaseMutex which fails with error ERROR_NOT_OWNER.
(TryEnqueue from UI Dispatcher can be called in the thread to avoid the crash)