5.14 Muay Thai Free Cam Bug

I noticed with borderless mode in video settings, (cause I use duo monitor and like to see load screen when I utilize my second monitor for other purposes.) I started the game with muay thai lee sin, (in free cam mode.) As I dragged my cursor across to the right, it actually left the league client entirely to my second monitor without me actually alt-tab. This problem doesnt exist in other video settings but borderless mode. I was able to re create it in a custom match right after. Locking the screen, then unlocking seems to fix it. This happens right at the beginning.