I can now confirm that the issue is caused by a drop fired immediately after the grip. Here it happens consistently - every time and with the editor as well as a packaged game. I’ll play with a counter on the input trigger and come back with some results…
Edit but as said before it happens only with some objects (door / drawers) and not with others (pickup cube, gun, bottle) so I find it hard to see the reason on the side of the Controller side…