If you sell an active item, (maybe only with full slots). If you also click purchase on a new active item quick enough it takes your souls, purchases the item, but doesn't actually buy it.
I saw earlier that if you buy siphon life get stacks and sell them it will delete the hp even if you rebuy it. I think with the item changes that some of the items are a bit buggy especially with some of them just recently being changed.
