Hello Nick Rustemeier,
This issue happens because the Windows App caches old feed discoveries from Azure Virtual Desktop or Windows 365, leaving orphaned application IDs in the local database even after you reprovisioned the backend.
To clear this icon, open Windows Settings, navigating to Apps, selecting Installed apps, finding Windows App, and clicking Advanced options to perform a Reset.
If you prefer an automated or deeper cleanup, you can close the app and delete the %localappdata%\Packages\Microsoft.WindowsApp_8wekyb3d8bbwe\LocalState directory, which forces the client to pull a clean, current workspace configuration from the cloud upon the next launch. Keep in mind that resetting or deleting this folder will require the user to sign back into the Windows App, but it completely resolves the duplicate icon conflict caused by the stale feed references.