Actually, it's not what I expected. The RDS session is created at the gateway, user gets logged into one of the hosts in the host pool and the app starts running. I can see the user in task manager is active, the app is running but at the client, no connection is made and all the user can see is "RemoteApp" Starting your app and it hangs forever. It's as if the remote desktop software is failing to connect but the session is actually running.
It looks like this may be something new with Windows 11 22H2. Several systems are now experiencing the same issue, all now running 22H2. I've tried the RDGClientTransport regsitry entry, that seemed to work on one PC but not the rest. Something seems broken in 22H2 with remote desktop apps. Is there a known resolution?