Floor has darker areas??

Hi I am new to UE4 and am having trouble understanding what is making my shadows act this way. There are straight lines of darker areas on my floor, and that line doesn’t even seperate two floor pieces. Its the same piece. Please help.

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Have you rebuilt your lighting? Click the “Build” icon at the top of your main window.

Yes I have

Does the model have a secondary UV set for the lightmaps? If so, make sure that the entire floor has its UV’s connected without any seams in between. Also check your model to see if it has overlapping vertices occupying the same location.