Performance Problem pls help

I’ve played around 200 hours on game pass and 150 hours on steam. There wasnt really much of a problem on game pass. I bought on steam when they announce dlc and even thou i get 100-140 fps mostly this thing called “%99 fps” drops a lot to around 10 and game just shuts down middle of match. Sometimes it happens 2 matches in a row sometimes doesnt happens in 4 matches in a row. I’ve tried to lower graphics but didnt work and i dont have any problem with other games (such as R6). Is there anyone encounter this problem and know how to fix it ?