@s9205307-810c679a
By definition, a “convex hull” is a “convex” shape, which means it is a single shape with no holes inside it and no indents on its edge.
What you draw is a hole inside a shape, so it can not be supported.
The reason for that is it is much faster to test if 2 shapes are colliding (overlapping) if both of them are convex. If we allow holes inside them, then the computation will be much more complex and time-consuming.
Can you explain what you are trying to do a bit more? Maybe you can consider using 2 or 4 convex shapes instead?