Lights are turning out very dark

Hello together,
I am still very new to the world of UE4, but I am already wondering why it seems that my floor is a lot darker when the floor in some of the tutorials I found? Is there any easy fix to get normal a little mor light colors back without using an older version of UE4?

The only thing I did was creating a blank project and set it on maximum for Desktop. The table and the chairs look normal. It seems to me that it is just the floor.

Thanks for any answers!

Regards,
Daniel