LEAGUE OF LEGENDS RANDOMLY TABS OUT WHILE IN-GAME

So this happens to me at least once in every single games that I play. It randomly tabs out to the desktop while I'm in the middle of the game and this has been repeatedly happening from the last couple weeks. Never had this issue before it just started last month up until now. Can someone tell me what might be going on and provide help or something that I can do to stop this. Thank you in advance :)[slayer-jinx-unamused]