RDP not working on hyper-v server 2022

Question

I can only connect to any hyper-v server from hyper v manager on the fysical host. 
 When the connection is up and running i can start MSTSC from my local windows 11 and connect to the server and take over the session. 
 
 if i try to connect directly to the server i can logon but the connection gets droped. 
 
 Sophos Endpoint Agent is the problem. 
 deinstall it and the problem is gone. 
 I have not found the right setting for sophos yet to solve the problem. 
 i did find out that changing the setting of the firewall it is working on one server and not on an other.

Sophos User930 · Accepted Answer

Glad it helped. It is a Microsoft bug (race condition) in the Desktop Window Manager (dwm.exe). It can happen in older OS as well but seems to be more easily reproduced on 2022. The other option, rather than adding a second core, is to exclude c:\windows\system32\rpcss.dll from real-time scanning but not recommended. 
 Basically while COM is being initialised on one thread in dwm.exe, which causes rpcss.dll to be scanned, another thread of dwm.exe tries to make a COM based call and fails as the initialising of COM is not complete at that time. The scanning changes the timing ever so slightly. This is why the error in the event log is essentially COM not initialised. It retries a number of times but each time it has the same issue. 
 Thanks.

Ferry van Dijk · Answer

That was the trick.

RDP not working on hyper-v server 2022

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