Thanks for your reply.
I figured out what the problem was. I didn't know how to make proper "rooms", so my entire house was made as only 1 pavement, with walls inside.
The ceiling light was messing the shadows. After deleting the floor and making proper rooms, the shadows were automatically corrected.
I am posting the same photos, made the exact same size.
Quality 3:
Quality 4:
If anyone have happen to have this issue, just make sure there is no wall where your ceiling lights should appear.