game minimizing when i flash

i have my M4 button as my flash so i know when i need to flash walls. It is my personal fail safe so i don't waste flash. But for the past while when i use my flash the game minimized and i was dc'ed. Thought it was weird. happened a couple of times after ever odd week. the past 2 days it has happened 5 times. i have been spamming Caitlyn in bot lane and i normally see the bug when i flash (M4) and E combo. I don't know if a dev will read this or if that is any help but that combo seems very frequent. when i go to flash E Q as Yasuo the bug happens as well.