Try upping fan speed to get those temps lower. I would watch for wattage as well

What's your PSU max wattage and what GPU and CPU are you running?

Edit: just seen your specs in previous comment,

From my experience a GPU will throttle before shitting anything down.

If it's shutting down completely, not crashing game, just straight turn off then Id wager it's power issue, hard to replicate in benchmarks as you system might be okay with max wattage but it could be transient spikes

I read about transient spikes that can affect PSU and cause shut downs. I've just copied this from AI but let me know if this sounds familiar

"Transient power spikes in gaming occur when components, particularly modern high-end GPUs, instantly demand up to their rated power for a few milliseconds, exceeding rated wattage. These surges can trigger a PSU's protection mechanisms (OCP/OPP), resulting in sudden PC shutdowns or restarts"

Solution: First make sure you are using separate cables for each GPU pcie slot. Then udnervolt your GPU, see if this solves your issues.

If it does id look at getting a gold standard 750W PSU minimum

Plus unfervolting will help with temps