This doesnt happen in every room with the character.
If this doesn’t occur in every other room we can assume that the issue is with how your lights are setup in that room.
If you can reproduce this in a blank project and can provide list of steps for me to get the issue to appear on my end, then we can investigate further.
For future reference please look at the “Before you Report a Bug” Section Here: Einen Fehler melden - Unreal Engine
Following the steps listed is the best way to get quality assistance.