I managed to resolve this issue by replacing the PSU ultimately. I decided to go for an ATX 3.0 model: Corsair RM850e.
I know the ATX 3.0 PSUs have better management of power fluctuations for the GPU so I don’t know if that’s why it’s fixed the issue completely but I haven’t had a single crash/power down since I did the upgrade (and it’s been a couple months since I originally posted!)
I also note I’m still on driver 537.34 currently (not the latest but I left it as long as possible to be sure it wasn’t something that was patched out of a faulty nvidia driver issue. This was the drivers I was on when the problem first occurred, so it was definitely the PSU at fault - not GPU or drivers.
I can now play the game on max settings with zero issues even if I have twitch and Spotify open on a separate monitor.
Hope you guys having the same issue manage to resolve it also.
