--> I would like to reference this thread here because I am experiencing vary similar behavior <--
I am passing through a GTX 1050 to a Windows 10 VM. This VM serves as a HTPC and is physically connected are two 4k LG TVs mirrored via HDMI. This was working perfectly for months (since December) but I've recently started experiencing issues where the TV downstairs is not detected no matter what I do (the upstairs TV works fine). After reading this thread and @ckoepf's technique I learned that I can turn off the VM, disconnect both HDMI cables, turn on the VM, wait for the OS to load, then connect one hdmi cable at a time. This will make the VM recognize both displays until it's rebooted, then it goes back to only detecting the upstairs TV.
There have been no changes on the VM, but unfortunately I have made several changes on the Unraid side which are listed below:
1. I connected a USB cable to my TrippLite UPS and started the apcupsd daemon. (We recently had an extended power outage which drained the UPS and caused the Unraid server to power off unclean.)
2. I upgraded to Unraid 6.8.3 from 6.8.2
3. I installed an old WinTV-HVR-2250 tuner card in the PCI slot next to the video card so that we could watch OTA channels for local news broadcasts. This also required me to install the "Unraid DVB" plugin so that I could load a custom image (LibreELEC 6.8.3) that contained the drivers for this card. And finally TVHeadend Docker container.
I have since reverted the changes in point 3 thinking that was causing the issue (Removed the tuner card, reverted back to vanilla Unraid 6.8.3, Stopped the TVHeadend docker), but no dice.
@ckoepf were you able to find a solution?
I'm sure I'll be asked to upload a diagnostic zip file, but is there any risk in doing that on a public forum? (Is there any confidential information exposed in those log files, passwords, etc?) Sorry I'm a little new to the Unraid world.