Ps5 keeps turning off only on ps5 games.

My ps5 has done this for the longest time and i got tired of it so i took it to a repair place and we thought the problem was the fan, and they tested it they said and they said they had to replace the whole fan for 220 dollars so i did it and just an hour ago i was playing the last of us 2 ps5 editon and boom it does the same thing it did, js randomly turns off, and if i try to play a ps5 game again after it turns off once it will turn off in exactly 20 minutes. Idk what to do ive spent so much money and theres still something wrong pls help.