This is a fairly high junction temp and sounds like a cooling issue. Try removing the side panel and see if the card stays cooler (want to see around 80C or so for junction, below 90C is okay. If the card is till getting to 100C plus on the junction contact manufacturer support as it sounds like the card is having a cooling issue.
From what I read at the time, 110°C for the junction hot spot was fairly common for factory-OC cards and
not considered an issue by AMD. My own 6800 XT that I had at the time occasionally reached the infamous 110°C and just throttled down without issue. It was from a newer production batch though (thanks the chip shortage crisis for that !). Also noteworthy; the other sensors of the card would stay within the 70°C - 80°C range.
The shutdown could still be from a PSU, as a CPU or GPU hits these higher heat numbers they can have increase power draw and it could be the PSU is not keeping up. However I would first look at that GPU temp.
I don't think so. During our tests, we moved the card into my own system where it would exhibit the same behavior.
In the end, we "fixed" the issue by installing 2 extra fans blowing directly on the card.
