The last week it got so bad I couldn't boot anything at all, no Live-USBs or anything.
So after months of trying to find the problem I finally couldn't narrow it down any more than to the MB or the CPU. Since I had so many errors that pointed to the CPU I decided to open a warranty ticket with Intel. They accepted after I presented my evidence of my problems and replaced my CPU with a new one.
Very nice experience dealing with the support, and I'm glad I bought the boxed and not the trayed version of the CPU since the trayed had shorter warranty. At least for 11th gen, I think the warranty aren't differentiated in the newer generations.
OK, seems like Unpackerr is the problem and not my setup. I didn't think it was Unpackerr at first because I have three more instances that is running :latest just fine. Perhaps that's because they have Sonarr connections and the non working ones haven't..
I downgraded to version 0.10.1 for those with "[PANIC] runtime error" and that worked.
Yivey_unraid's post in SHA256 errors, trying to narrow the source down - any advice greatly appreciated! was marked as the answer