I can only agree with the anonymous colleague. Mine runs absolutely stable. In everyday use it runs without OC/Undervolt and I've had absolutely no stability problems so far.
As he/she has already indicated, such stability problems are really difficult to pinpoint and can come from virtually any component in your PC. Hope you get to the root of the problem quickly.

So my Stock is running perfectly. No crashes or anything else so far. There has been a new driver for 2 days, but you can only download it directly from AMD and not via the software... -80mv is ambitious. The best cards so far run with max -50 to -60mv in games! Don't rely on the benchmarks from 3dmark or something like that for undervolting. Mine runs stable with -35 and 2650 on the memory in ac shadows. In Stalker approx. -50mv and 2700 memory. If you need help come to pcgh forum-> Rdna4 laberthread. Otherwise check your setup, it doesn't always have to be just the card, sometimes a hardware change wakes sleeping dogs and other weak points come to light...

Many thanks for your answers. I know that not every game can run stably with the same settings and 3D Mark is really only for the highest possible score. I will download the new driver from AMD directly and test it. Unfortunately, it can't be due to the other components, as I had everything the same before and only changed the GPU from 7800XT to 9070XT.