Question Crashing GTX 1070

Oct 23, 2021
CPU: i5-4670k
Motherboard: ASRock H87 Performance
GPU: MSI GTX 1070 GAMING Z(4 years old)
PSU: 600W
Monitor: playing on 144 MHz (not sure if this matter including just in case)

Unfortunately since couple of days ago I have problem with crashing graphics - it started when I was playing TW Warhammer 2, whole screen turned into artifacts, I could still hear the sound from my music player, after couple of seconds screens restarted and game crashed. I tried running Heaven Benchmark to see if it crashes there and so it did. Tried clean install of drivers (uninstalling first with DDU), not helped. GPU was running quite hot (over 80) on Heaven, so tried to apply new paste - this helped, max temp. was 70(and still is) and it did not crash during Heaven and later while playing, so I though problem solved. Unfortunately next day problem continued ... I tried downclocking a bit (-50), but did not help. I am able to play some less demanding games without crashes.
I also tested with my old GPU (GTX 770) and everything works without crashes. Is there something else I can do/test ? I really don't have funds for new GPU, so I am hoping for some miracle.