expanded farmhouse

Tile issue after upgrading house to include the cellar. I have an issue when upgrading the farmhouse. Everything works fine up until I upgrade the house to include the cellar. The next day the tile issues arises as seen in the image below. Things I have tried: Updating all mods (All mods...

This is my farmhouse (vanilla game). The diner, solarium, and castle library (in the cellar) are still WIPs, but I like how the rest of it is set up. I want to get one of the trees with a purple pot from the claw machine once the theater is open for the solarium. I need to figure out lighting...