Promotional game bug [CLIENT]

On multiple occasions I have been one for one in my promotional games and have been informed that my series has failed. I have linked my most recent games, the leona was the first promo game win and the nocturne game was the first loss. Promo failed. During these losses I have always had an AFK team member at some point, but that's the only common feature I've noticed on the multiple occasions this has happened. Is this just a case of - "You have been granted a free loss the next time you enter your series. You're welcome. Riot games".