Hmmmm, your MMR (your “real SR” that is tracked internally and used for matchmaking) does move faster than your displayed SR, so a few wins or losses in a row could make a larger difference in who you match with than your displayed SR would lead you to believe. If you imagine that every win or loss is roughly 75SR that might be closer to where you match.
If you get a mix of wins and losses with no extended streaks your SR and MMR should quickly become nearly equal. I would not expect this to be noticeable above the usual randomness of team formation until you were on a streak of 5 or more in the same direction. I’d also expect it to take as many losses to neutralize the effect of a win streak completely and vice versa.
Kaawumba has done a pretty good job of explaining it all, along with an absolutely comprehensive list of references to everything the devs have told us about how matchmaking works.