I have the same bug happening here on UE@5.7.4.
Happens on a scene where the only movable light is a directional light and a skylight.
My fix has been:
- disable “force no precomputed lighting”
- build > build lighting only
- enable “force no precomputed lighting” again
- build > build lighting only
have no idea why it worked, i’m just hoping it won’t break again… ..・ヾ(。><)シ