I must have missed that, normally I do make them more than 6 units anyway but with this one, I made a few of them a certain size and when I realized that this was wrong for matching them together I reduced the sizes by rescaling them.
This has given the problem of the walls, floors, and ceilings being less than 6 units (quite a lot less).
It does not give a reason why I have the same thing on the rectangular unit (top right), this is a solid unit of 40 x 32.5 x 13.5.
HP Pavilion Laptop - AMD A8-4555M APU with Radeon(tm) HD Graphics - 1.6GHz, 8GB Memory, Windows 10 Home, 64-bit Operating System.
I've got something to say - It's better to burn out than fade away.