MOGRT exported with video from Premiere lightens the whole screen

I exported a lower thirds MOGRT from After Effects which seems to be working perfectly fine. It even plays back in Premiere exactly the way I want it to. But when it's exported, when I watch the video- the whole screen lightens a bit during the graphic and darkens back to normal after it goes away.

Update: I checked Render at Maximum Depth and Render at Maximum Quality and the issue is resolved but I'm still wondering why this happens and if I should have to check these two boxes everytime I export because I generally don't use these unless I'm compositing graphic based layers. I want to understand what's happening here not just solve the issue.