Hello there,
had some crash into gaming as well. What i saw on my side is a bad fan curve. Maybe begin to check yours if it is not default with wrong values. Had to make my own. In fact, i have a problem with the gpu hotspot, wich brought me to check what was wrong and i saw that my curves were not maintained at a normal level to prevent hotting the gpu. I may think you still can have a bad gpu from the industry, not that this is the problem you get, but we never know.
What i had for the fans default was that:

What i changed for a normal fan curve:

What i made for gaming:

I do not say your problem is this, but you can still see if it help with temps and if that can prevent some crashing. Give it a try, that may be as simple as this.
That may be too, in case you get high temps, a bad pasting of the gpu. That may recquires you to repaste your gpu with a better apply and a better paste. Notice that each paste have a different W/mK. What i learned is that the firms usually use a 3W/mK standard paste. For my gpu, i got a 14W/mK. The higher, the best.
Just take care of one thing: This imply loss of warranty in some countries if you do decide to change it by yourself. Where i am, warranty can jump out when i screw the sticker on the screws.
You better check, if this is what you decide, AND if this is your problem, what happen of the warranty in your place.The RMA is sometimes the better solution.
To check the temperatures, i used the latest HWinfo64. That's where i found out that i had a gpu hotspot with a difference of more than 30c° from the overall gpu hotness. When i was reaching 65-70c°, my hotspot was reaching up to 100-104c° and that was causing the security crash of the game.
Hope it will help you a little bit if you're still on your problem.