(HELP) R6 FREEZES

Every time I play Rainbow6 my PC is working totally fine until I play a second match. In the second match my game starts freezing for a few seconds and also won’t stop constantly freezing in the next rounds. When I close the game and restart it’s working but only for 1 match. I think it isn’t the hardware because the first match is working fine on high graphics. I can’t explain why this is happening, any ideas?