Item duplicates with 1-9 swap keys and overwrites other items

when swapping items spamming pressing 1-9 around Items will disappear and eventually duplicate.

How to reproduce:
1: take 5 random items/blocks
2: put them in the hotbar slot 1-5
3: go to the creative inventory and hover the cursor over a empty slot and let it rest on one of the slots
4: spam "typing" 1-5 and the items will swap and swap and then duplicate, overwrite and disappear...