No Playback in Resolve 18 with Radeon Graphics

Specs:
Ryzen 7900X
RX 580 8GB (previous)
RX 6650 XT 8 GB (Current)
32GB DDR5 RAM
AsRock Mobo

Several months ago, don't remember exactly when, probably around a major Windows 11 update or Radeon Graphics driver update, I ran into what seems to be the common error where Resolve won't play anything on the timeline. Error log shows the usual "Failed to create OpenCL context" and "Failed to initialize OpenCL board manager for [6650 XT]", etc.

This is consistent for both the old RX580 and my new (installed today) RX 6650 XT.

I've tried all the solutions here: Revert to Resolve 17, upgrade to latest beta, DDU and reinstall Radeon drivers (including Safe Mode), disable iGPU in BIOS, etc. So far nothing has worked. Here's the Resolve log .zip file. Any other ideas besides full Windows reinstall?

Edit: Upload NFO (in zip)

[Dwaine Maggart]

You appear to have displays connected to both the Radeon RX 6650 XT card AND the internal Ryzen iGPU.

You need to have all displays connected to the RX 6650 XT card.

If that doesn't solve the issue, open Windows Device Manager, select Display adapters, then right click the USB Mobile Monitor Virtual Display adapter and select Disable.

If neither of those help, send another Resolve log and NFO file generated with the above things done.

You appear to have displays connected to both the Radeon RX 6650 XT card AND the internal Ryzen iGPU.

Not the case. Also, what is telling you this?

You need to have all displays connected to the RX 6650 XT card.

Yup, that's what I've got. One in DisplayPort and one in HDMI.

If that doesn't solve the issue, open Windows Device Manager, select Display adapters, then right click the USB Mobile Monitor Virtual Display adapter and select Disable.

This fixed it! Amazing that it was so simple! I don't even know where that device came from or what might possibly have been using it.

If neither of those help, send another Resolve log and NFO file generated with the above things done.

Fixt! Thanks so much. This has been bugging me for MONTHS!

Edit: For better stability and compatibility in the future, it seems the dev team might want to figure out a way to just ignore all devices that are not that are not the primary discreet GPU (if present).