There appears to be a stash dragging bug. It looks like a off by one error:
When dragging a stash tab from right to left I have to drag it one further than indicated.
Before: A B C
Goal: A C B
To get there I have to do drag C before A and release.
Dragging a tab from left to right works as intended and indicated.
I hope the video explains it better than I did.
Thank you.