This happens alot when I rotate objects, whether I do it with the camera roll tool or the layer rotate tool. It seems that this happens if you change the fill properties/add or remove ponits to a shape after you've applied the initial fill. It can be fixed by deleting all the shapes and starting again, post shape edit.
This doesn´t explain what is happening in your situation described, but.....was thinking...Instead of putting the 4 white/grey rectangles around your football stadium, why not just add a new vector layer beneath your football stadium layer and make a big, rectangle that fills the entire viewing screen or area you want.
That way your football stadium is always above a solid white background.
(Or in the project settings, just set the background to white -or whatever color you want- and render. If you want the entire background to be that color.)
Then rotate your football stadium screen.
Tip on that - add a bone to the football stadium screen layer and rotate the bone. Rotating the object without a bone(s) causes strangeness.
Cheers Toonz, but that wouldn't work for most of the situations where I encounter the problem (in this case the camera does a massive zoom out to reveal London, England then the world! THe grey is the colour I chose for London:)) The original post just demonstrates the simplest scenario I could find.
It looks like you've created what I call an "illegal" fill in Moho. Moho tries to detect these situations and prevent you from creating the fill, but there are times you can trick it into still allowing the shape.
A fill in Moho is defined by the boundary curves. If you have curves in the interior of a shape that connect different points together, then the boundaries can become ill-defined. That's probably the case here.
If you want to post a copy of the Moho file, I can figure out exactly where the problem is and show how to avoid it.