Potion Split Bug

[BingusDingus]

Here's the bug; I have 13 potions of speed in a bag located in my stash, I tried to split them 6-7 but the moment I confirmed the split the other stack never appeared and all I had was a white rarity potion of speed icon in a slot that i could interact with.
The only solution I found was to remove them from my stash and split them in my characters inventory.

Also just came across another bug, the Diadem of Arcane Synergy prevents you from performing with instruments.