How to not stretch a shape I put inside a server rack in draw.io?

Question

Every shape I place inside a server rack is stretched out over the full width of the server rack. I need to place some smaller items in the rack, how do I prevent the stretching?

I have tried to add the style property resizable=0; but that gives no result.

Answer 1

A bit late to the game, but unchecking Drop Target in the rack properties seems to have done the trick.