I used all 36 of my available room budget to build a stairway vertically. Attempted to move the last one in the chain down to the entryway on floor 1(hoping to force the entryway up a floor somehow so I can have a basement) and now I’m unable to go up to floor 7 in the UI to access that room and remove it, even though it still exists.
The entire floorplan is now locked from being edited as a result.
Edit: I was able to remove the room with a script command so at least my house is fixed now.