Try adjusting your brightness level to something else than what you have now, press Done then come back to the Video Settings and adjust your brightness level back, should solve it.
that's not a bug I'm pretty sure it supposes to work like this...
I can bread llamas... so...
I have the same issue
(MC-148915)
Try adjusting your brightness level to something else than what you have now, press Done then come back to the Video Settings and adjust your brightness level back, should solve it.