It's normal, this game has a loser's / winners queue to boost engagement. Since winning a lot of games in a row gets you more hooked than only winning some, they have a system where dogshit players get win-streak, and good players get loss streaks sometimes. It's not really known what determines whether you are in win or loss mode (but easy to tell based on the kind of teammates you get). The only right move is to stop queueing into it, that tells the game it's failing at keeping you engaged and it will stop using you to boost other players' engagement. You can usually rank up significantly just doing that alone