My game keeps flashing in the left bottom corner of my screen.

When I logon it's fine same with the loading, it's just when I start to play in a world. The bottom left part of the screen will flash white and it won't stop. I've tried resting my game and even making a new world, but it still happens and the game runs just fine on 1.12.2. it's just with 1.13 that it has problems with.