Windows MultiSession 2004 Login / RemoteApp issues

Question

Having an on going issue that is just driving me crazy

We have 4 GPU WVD VMs (running version 2004) using Stamdard NV12s size and the NVIDiA extension installed for the Tesla card setuo in device manager. All 4 have the same issue.

On boot the machines are fine. We have RemoteApps running from them and users can access them. We as admins can RDP into the VMs fine. After some time, we get calls that users cannot open Remote Apps. On testing the RemoteApp it hangs trying to load. If you click on the dropdown to see thw login, its hung at Preparing Windows. Trying to RDP into the VM gives a black screen on login. You can bring up task mgr witb CTL-ALT-END and open things like device manager and cmd prompt / etc from there, but the screen stays black.

We also have OneDrive running on the VMs that should start on login, but of course never does due to black screen. OneDrive is also set to run with RemoteApps using the RailOnce registry key and setting key to start onedrive /background.

I have no clue what is going on here. Is it OneDrive failing to start with the remoteapp or login? Is it graphics driver? Stuck and in a bind. Cant keep waiting for users that are already logged in to finish up and logout then reboot the VM to get it working again...

**EDIT
The issue we have is exactly the same issue as a user posted 3 years ago on the old technet forums. The scenario the user mentions is 100% the same as what we see. There are a bunch of things people have done to try and fix, with nothing working fully.

https://social.technet.microsoft.com/Forums/windowsserver/en-US/3fdfa58b-fe1b-4546-85d2-d43dac9bcc10/black-screen-on-all-new-connections-sessionhost-has-to-be-rebooted?forum=winserverTS

Please dont tell me to reboot the machines or build new ones. Been there done that. We've resized the VMs to with more CPUs / GPU power and there is no change After a while, Black screen on login for any user that tries to get in.

Microsoft released patches to "fix" this in the past apparently, so the cumulative updates systems get should have the older updates in them, so anything patched as of August 2020 would have the older patches released to "fix" these issues.... Looking around the web, there are many folks having the same issues with even new OS's. How can Microsoft not have some kind of resolution for this after 3 years?**