I replied in similar topic that I also created when trying to get this RX 6800 XT working, long story short I swapped it with nVidia RTX 3080 and went with proprietary drivers as usual. They always work for me just fine so that is my solution, however like I said elsewhere I will try to switch again with introduction of RDNA3 GPUs sometime in near future, so by no means am I giving up on AMD. I like that particular piece of hardware, it is just the software part which did not impress me at all. But at the same time it is way too soon maybe and things will iron out in next weeks, however I’d much more prefer to go with nVidia right away then which guarantees me no issues at all when running proprietary driver suite.
Thanks for suggestion anyways, may come in handy in future.