In-Game looks different than Viewport

To me it looks like it might be an issue with auto exposure. If you set it to fixed at log 0 you should get a consistent result.

So i have this problem:

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But it isn’t only with the fog…
If it is night time it looks a lot better(brighter) if you are looking simply through the viewport rather than if you are playing, what i causing this complete difference between modes? How can i fix this