MAC: Postgame results locks client below bottom of display

After a game playing on a mac, where I cmd-tabbed during loading, the client is locked and cannot be dragged up beyond the shown level. This was with no external displays attached on an early 2015 mac, 2560*1800 built in display, OSX version 10.12.6, client patch 7.19. This doesn't affect other apps running on the machine, only LoL. You can't leave a post game screen without exiting the client and logging back in again.

Expected: I can move the client anywhere I like. Actual, it is locked 1/2 way down the screen.