Black screen on client load

I've been having this issue for about a month now, it seems to go away and come back at random. After champion select when the game is loading into the client my screen will go black, mouse is still on screen, but i cannot alt tab, ctrl alt del or escape the screen in any way. only solution so far is to do a hard reboot and reload the client, it usually works on reboot. I've fully updated my bios and video card drivers. System information as follows: b450-f gaming mobo, Ryzen 2700, 5700 XT pulse, 16 gigs corsair vengeance ram, WD blue m.2 SSD, 750 psu