GPU has fallen off the bus | GPU crashes after a while under load (ie. playing games)

That is actually what I have been recommended elsewhere as well. Haven’t ordered replacement just yet though.

I am now 99% certain that this was an issue of this: https://knowledge.seasonic.com/article/20-focus-plus-and-gpu-potential-compatibility-issues

After I got replacement cable from Seasonic I have yet to encounter this crash.