Need help with room overlapping on top of each other sometimes

Hello guys, i need help, i follow a tutorial

This one : https://www.youtube.com/watch?v=4ddbnQIuwAM&list=LL&index=15&t=4431s

and everything seem to work just sometime some room overlap on top of each other and i don’t know how to make it work and not make them overlap on top

they don’t overlap on the side only on the top of each other.

If you need anything to help me clear this out i will gladly provide it.