After the new patch (9.14, EUNE), I encountered a weird bug. Items that are not used on characters will randomly disappear from the bench. Unfortunately I do not have a video. The bug seems to have some relation with teleporting to other players map, because when I am on my map I would have the items on the bench, then I would teleport for a duel, and when I teleport back, the items on the bench are gone. This is a pretty big issue and I hope it will be resolved before twitch rivals because that'd be pretty awkward. :D
Edit: the opposite also happens, items appearing from nowhere, although they cannot be used, here is a video:
It seems to be something wrong with items staying outside of characters, notice how before teleporting I do not have items, then i teleport and 2 items appear.