Flashing White Line when Switching Apps

Just tried in safe mode and it still does. It only does it when there are 2 apps open. It's crazy both my original and replacement would do the same thing.
 
Does it happen with any combination of applications? One thing that I find interesting is your keyboard stays active. If I start typing in chrome or Textra and then initiate an application switch mid sentence my keyboard does not stay active when I return to the application that I was originally typing in.
 
No it doesn't matter what two apps I have open. And it does it whether the keyboard is open or not.