I can't access after instaling MAC OS BIG SUR

Hello,
I recently installed the Mac OS BIG SUR update on a MacBook Pro (13 inch, 2020, two Thunderbolt 3 ports). After that, I launch the game, everything is fine. Then comes the launch of any game, when downloading the game, the game does not launch. I have to quit the game and restart it to get access to my game.
I should know that I play with my brother who has a Mac dating from 2013, with the new update and he has no problem to access his game.
I have reinstalled the game twice, cleared my mac, fixed with the ONYX app and the problem persists.
Can you help me solve my problem please.