Server 2022 WMI Issues

Hi there, I have a Server 2022 with WMI problems affecting the server in a few ways.

The server is a domain controller, RD Broker and hosts some files also. The server actually operates ok for the users day-to-day.

I discovered the issue when opening AD Connect, getting an Invalid Class error message. When running various fundamental commands at the command prompt (e.g. tasklist) I get the same error. When looking at the WMI Control in Computer Management again - Invalid Class.

I have tried various fixes found online such as verifying the WMI repository (it comes back as consistent) but I think I've reached a dead end. I don't want to restore the server from backup as I believe this issue has been ongoing for a couple of months before it was discovered.

I can't get in to the Remote Desktop part of server manager to replace the certificate, and the certificate expires next week.

Does anyone have any ideas please? Any help greatly appreciated, thanks.

Chris