Draven combining error, multiplies after carousel

I had just ended a round . I had the following: -a 1 star draven with a needlessly large rod equipped on the field -a 1 star draven with no items on my backline -a completely full backline

Carousel round starts, i see another draven with a needlessly large rod equipped, decide just to get him for level 2 draven I pick him, but the next round starts like this: -a 2 star draven with a needlessly large rod equipped on the field -a 1 star draven with a needlessly large rod equipped on the field (which had been placed there due to having a full backline) -a 1 star draven with no items on my backline

So effectively what happened was i was given a free upgrade on my draven that was on the field and the draven i picked went to the field as well. If i had to guess, i would say it has something to do with picking identical character+item on both carousel rounds while having a full backline causing some weird combination error

I didnt get a screenshot but regarding positioning of the round ending before the carousel: the draven in my backline was on the far left, and the draven on the field was in the back, two tiles from the right