Pro Max 16 Premium MA16250 odd graphics corruption

Having very intermittent graphics corruption appear on the screen in the exact same spot.  Only flicks up on the screen for about a single frame and then disappears.

Always in the same spot, bottom left.  Always about the same size.  I tried capturing it with screen recording, but it didn't capture it.  I had to film my screen with my phone.

265H, RTX Pro 3000, 32GB.

I have not been able to replicate the issue when forcing dGPU.  I have also been unable to replicate in Ubuntu, or the BIOS.  However, the issue is so intermittent, it could just be that I didn't give it enough time.

I can be free of the issue for hours, and then it happens a few times in a few minutes.  This makes it very difficult to troubleshoot, as I'll try something and think it may have fixed it, but eventually find out it hasn't.

It does not appear to be heat-related, it has happened shortly after turning on from cold, and CPU/GPU temps all seem fine.

I have a reddit thread on the issue here:

https://www.reddit.com/r/Dell/comments/1pyud21/weird_graphics_glitch_on_pro_max_16_premium/

and so far there are 2 other people reporting the exact same issue (one via PM, the other in the thread) which leads me to think it's likely a software problem rather than a very specific hardware problem.  I'm reluctant to just get the motherboard replaced because of this.

Laptop shipped with Ubuntu, but I installed a stock Windows 11 image with drivers manually installed.  Also tried slipstreaming the WinPE drivers onto a Windows 11 installer and reinstalling with that.  No change.  Have tried various combinations of chipset/graphics drivers from Dell and Intel/nVidia directly, but no change.  On latest BIOS.

Also have the odd intermittent freezes mentioned here:

https://www.dell.com/community/en/conversations/dell-pro-max-laptops/pro-max-16-premium-ma16250-stabilitysystem-freezing-issues/69008950565edc4dbf22f7a3 

Almost like CPU is jumping to 100% for an instant and jamming the system up, but this is not the case as usage is very low <10%.  Other than that, the machine has been rock solid, no crashes or unexpected reboots.