I'm the OCCT Dev ( https://www.ocbase.com ).
I was recently warned that there was an issue with AMD GPUs and my VRAM test.
Testing has shown that using any driver above V 20.4.2 result in my test being unable to allocate the memory - and then crashing.
I tried to contact AMD to no avail yet - as i do not own an AMD GPU, it's rather hard for me to replicate and debug this issue.
I updated my website to make it clear there's an issue - it's either on my side or on the driver side (at that stage, odds are on the driver side, but you never know ).
Sorry for the weird behaviour,