I just confirmed having the exact same issue, also on an RX 6950 XT. I've been stuck on an old (before mid-December 2023) version of the display drivers to be able to run DaVinci Resolve and a few other applications requiring OpenGL for UI elements, but now a few applications are having issues due to old drivers so I have been forced to upgrade to the latest ones. With any AMD drivers from mid-December 2023 and onwards GPU-Z will not detect OpenGL at all (just like a lot of OpenGL applications), but today I realised that if I unplug the HDMI cable to my soundbar from the graphics card GPU-Z detects OpenGL without issues and OpenGL applications work as expected. After plugging the cable back in GPU-Z again fails to detect OpenGL, _but_ when I turn on the TV connected to the soundbar OpenGL is back once more.
At some point in late 2023 the driver presumably stopped supporting OpenGL when an HDMI device is connected but no actual display is responding. I'm not familiar with how HDMI works in this regard, but since this used to work without problems I would prefer to have this change rolled back and be able to work with my computer without having my TV powered on for no other reason than to enable OpenGL.
