Seriously what is wrong with this game technically

This all started a patch or two ago. Alt tabbing creates a 5 second delay where you are forced to wait and watch the black screen. Now the game forcefully tabs me out for some reason while playing a ranked game. I cannot afford to be out of the game for 5 seconds during a teamfight! On top off all that i get fps drops and tearing on a high end pc (i hope they fix this soon). Loading screen is black for some reason with only names and champions visible. Game is literally unplayable atm.
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