[2021] Tier 2 room problem?

For any type of diagonal roof you need two thick roofs. Rooms are not allowed to have contact with air to be recognized correctly and diagonally having contact to air counts as having contact to air:

A B
B A

B being blocks, A being air. Diagonal contact, e.g. contact to outside, no correct room.
We want to rework this in the future, but it's working as intended for how the current system was made.