Disappearing Item + Selfbenching carrousel units during fight

[Ranked!] I put a on my during a fight. I put it on her exactly at the moment she died. The item disappeared from my item storage space (?!) but it also wasn't to be found on the shyvana. The wasn't just invisible, i got no item effects either. This cost me a few LP. Is this a bug or some banter that Shiv + Shyv don't go together? xD

[Ranked!] My bench was full during the carroussel, so my newly picked champion was on the field. Then i decided to leave the extra unit () on the field for the next fight and create space on my bench during that fight. the fight started, my units fought. I started creating space, but my voli instantly left the battlefield to appear on my bench even though he was fighting just a second ago. I used to do this a lot without experiencing this selfbench mechanic. If this is a bug, please fix it.