I was unable to reproduce this issue on my end by following the information your provided.
I used the following steps:
- in an empty map create a basic room (plain walls, floor, and ceiling made from the basic cube)
- place a stationary light with default settings inside the room (Bake Lighting)
- placed the Unreal Mannequin character in the room
- Move the camera and look for flicker
Have you tested to see if this issue appears with other skeletal meshes?
- If this only happens with this character then the issue is with your asset.
- If this only happens in that specific room there must be something else you are missing that makes that room different from a basic room with a single stationary light.
Also, I believe that the issue you linked is unrelated to this post.