I went to undervolt my three year old 4080 and noticed that at full load, my GPU was hitting hotspots of 110 degrees, despite only pulling 190W.
Opened it up to repaste it (because that's what I THOUGHT the problem would be) but this is what I found.
Cracked copper heatspreader with little bits of visible aqua oxidisation. Crazy.
After a like EIGHT WEEK rma process with gigabyte, I finally got her back and she's working good as new. Please check your temps, and maybe do so before a nice holiday when you're away from your pc for a few weeks.