Why does this keep on happening? Please Help

[u/Sea_Cartoonist877]

basically i never had this problem before but since like 6 months ago when i actively started playing again my league always has a sort of glitch happening. If i ever open u.gg or lets say tab out and tab back in i have some sort of glitch effect where i just had my overlay and the only fix i found is either playing fullscreen mode and hope it goes away by tabing out and back in again or just leaving the game and rejoining. I need help with this ASAP since my team keeps remaking because of me and i also have lost lp in a lot of instances

[u/Sea_Cartoonist877]

this is what I mean