High MMR matchmaking issues

Hey, I've just been noticing an issue that happens fairly often in matchmaking. This isn't meant to be a QQ thread, just pointing out some observations and questioning what is going. Often when I go through a good winning streak and I'm gaining a good amount of elo my mmr obviously rises. Then I get to the point where I'm winning 24 lp and losing 16-17 lp / game. However, I find that once I reach this point, the games change. I either have to win a close game just scraping by and carrying, or my team gets completely utterly crushed. So, why is that? It seems the games are very distinctly divided into close wins and frustrating losses that aren't remotely close games. Usually the opposing team is higher ranked overall with low mmr for their rank, while my team is lower ranked with a few higher mmr players. But who knows why the higher ranked players have low mmr? Maybe they just had a few bad games, but that doesn't mean they're at the same skill level as lower ranked players. Anyways, it just seems that there's a glass ceiling when my mmr gets to the point of 24lp/win 16-17lp/loss. The wins are close and hard fought, but the losses are just a prime example of unbalanced teams. Where is the explanation for this? It's annoying to keep hitting that glass ceiling over and over and it just seems to be a frustrating signal of a systemic flaw.