I am not sure that I agree that the void doesn't move, at least in terms of a particular location. You CAN fill a vessel with atoms, can you not, and that displaces the void in that particular location.
Void isn't a "thing". It's not composed of atoms. It's the "medium" in which the atoms move if you will, and even "medium" isn't the right word.
I'll have more to write and respond soon. There's a teaser.