Win a match with no leavers, still lose SR

So I played my first match of the day in competitive, we didn’t have any leavers and I experienced no lag or warning messages throughout. We won the match, but I still lost SR at the end of it. Granted I’m not great at the game, but it seems incorrect that one could win a game and still lose SR. It wasn’t super substantial as I’m a really low rank anyways, but still frustrating.