I am experiencing issues combining ammunition slots in the inventory. This video shows three issues.
In the beginning, combining rounds of one type will result in the slot becoming unusable and instead taking up the same slot as another type of round.
In the end, combining another type of rounds will not update the new stack of rounds.
Moving the slots around then caused other moved slots to teleport back.
https://www.youtube.com/watch?v=5SpyvD-3CHw