Quickplay MMR impacts your placement matches?

Stats:
Season 6 - W4 / L6: 2638
Season 7 - W6 / L4: 2602
Season 8 - W2 / D1 / L7: 2630 placement; End of season was W4/D1/L10: 2546

This season I won my first match; lost the next two; and the rests were all wins with one more loss somewhere in the mix for W7/L3: 2281.

The weird thing is, looking at my Career Profile, my stats for the season are significantly better across the board that in those previous seasons.
Which is understandable, given I was playing against weaker opponents.
But without it giving me stronger opponents even after stomping in my last series of wins, it appears as if it was low-balling my placement matches by the time it gave me a rank.

Addendum: Just played one additional match, another comfortable win with my performance being very solid. SR 2299 for us vs 2297 for enemy team - all gold rankss both team. New SR is 2305 with L3/W8.

So that’s an average of 100SR down per loss; with a specific increase of 24SR for an easy win which is part of a winning streak featuring several stomps and me popping off.