Task manager user control prompting for password

Hello, 

I got a problem concerning Windows Server 2019 RDC. No matter how we configure the GPO, we can't connect to users over the Task Manager without the password prompt. Got any ideas how to work around that? Both I and my colleague are Administrators on the network and got all permissions.

I know you can shadow people over the RDC manger tool, but the user we're trying to have assist with insists to doing it over task manager...