Originally posted by Beautiful Ham Sandwich:

Could be a heat issue, the game isn't all that optimized so even with your specs there can be problems if you underestimate the game. Check to see if your temperatures are normal, both with and without the game playing.

This is accurate.
I've got a 9600k and a RTX2070, GPU is usually at around 70C (~170F) and CPU around 80C (~175F)
Though thats with overclocks and running at 4k, max settings.