Items selling themselves alone

Hi, I've experienced the same bug twice in two days. Today i was playing corki, i had the trinity force and backed to buy a bf sword, i bought it, then a potion and at the same time i bought the potion my trinity force disappeared and i got the gold from the sell. i watched the replay and it occurred at the exact same frame i bought the potion. Now this is pretty annoying because i saw it only when i left the shop :/ If you need the replay or have any further question i'm right here.

Zbtx