Camera gets locked-on on the champ after alt-tab to the starting game

Since I have two screens, during game loading time I watch other stuff on my 2nd screen and when the game starts I click to the game, If i click to my main (gaming screen) the moment when the game starts, my camera gets lock-on on the champ without ability to remove camera lock (no "y" or button works), the only fix so far I found Is quickly to leave-reconnect. I consider it as a bug, therefore I post it here. It happens rather often.