Why Do My GPUs Keep Dying?

I’ve been using a Z8 series Xeon workstation for about two years now. A few months ago, I had an RX 5700 GPU installed, but it suddenly stopped working while I was in the middle of a game. After that, every time I turned on the PC, it would run fine for about 5 to 7 hours before the screen would go black — no display — and the GPU fans would spin up to maximum speed. Over time, that 5 to 7 hour window kept shrinking until the system would only run for 1 to 2 hours before crashing, and eventually, the GPU stopped working altogether.

At first, I thought the problem was just the graphics card, so I sent the whole system in for repair, but they didn’t find any issues. Now, today, while I was editing, the exact same thing happened with a different GPU — this is the second time it’s happened, and I’m worried it’ll go down the same path as before and stop working completely.

What should I do to fix this? Any ideas on what might be causing it?