Future lighting deciding to be whatever brightness it so desires

Watch the video, can you see the lighting becoming super dark, then super bright? I don’t know why it keeps going bright, but it’s driving me nuts! In my game it’s supposed to be dark no matter what! Does anyone know how to fix this?

It might be due to the Clock Time if you have a day-night script.

From what I can see it seems to be the environment map generating and then lighting up your environment, but I can also see that your lights are insanely bright.
What I’d recommend is turning down your lights to a max brightness of 1.

P.S disable the cast shadows property on the frame surrounding your lights, those aren’t realistic shadows