[MLO] interior disappearing in noclip

Hi everyone. I’m trying to make a mlo but I’m having a problem. As you can see from the video, if I enter or exit the interior normally, there’s no problem, but if I do it in noclip or activate noclip inside it or on first person, it becomes invisible. What could be the cause?

you should not no-clip into an mlo.

you need to set the collision material for the floor to one material and the walls etc to another material