Woah... This shouldn't be happening..

[Ouroboros]

Aside from making the .mat file to use blank in the primitive option I couldn't cause the same effect so I suggest deleting the floor and then placing another, perhaps stretching one you already have to see if it disappears as well.

Since you're not using a dev set up, I guess I then suggest maybe placing like doors or boxes or something and disable them/unlock them instead of having debug messages, any visual way of testing whether it makes it to the function or not will do.