Black screen

Sometimes before I enter loading screens with my mac my screen Just turns black and lose connection to the game but when i try to retry or close the the link it just stays in the black screen forever until i am forced to turn off and turn back on my mac. Now I'm currently being punished and forced to be waiting in lower priority cues because of it. Ive tried to uninstall and reinstall the game many times but the screen eventually returns which result in me getting punished for games i would be happy to play and finish. I just need to know if there is a way to fix this bug so i can not be unnecessarily punished for this bug.