4.19 black screen issue is not new

RiotMasterCheese — "We are investigating an issue post 4.19 where the game sometimes loads as a black screen when using ALT+Tab, causing players to quit out and re-launch."

I've had this problem for months! didn't happen every time, and i didn't understand how to report it as a bug so i didn't, just saying this wasn't a "new" issue that just came with 4.19.