It sounds like there is a problem with the handle of your nice Stealth Topas.

You are quite correct that the Topas and handle is not designed to do that.

It could be something is catching on the inside of the handle, in the case. Or that the handle guides have been torqued. I would have your case seen by a Rimowa store, or one of the Rimowa authorized repair shops.

You are covered. All they need is the ID Nr. off the case: Contact them.