New to the game and stuck in a weird Plat 1 loop. Is this just how ranked is?

Hey everyone, I’m pretty new to the game. I started back in January and don’t really know much about the community or how everything works yet, but I’ve been having some super weird experiences with matchmaking that I’ve never seen in any other game.

Like most people, I played about 25 hours or so of QP just to get the hang of things before jumping into Ranked. After my 10 placement matches, I got Silver 1. Then, over the next 5 hours, I somehow climbed from Silver 1 to Plat 2 playing literally only Zenyatta—mostly because I'm not that great and don't really know how to play anyone else yet, haha.

But then, out of nowhere, things got kind of bizarre. For the first time in 30 hours of playtime, I started getting matched with teammates I'd never seen before—trolls, AFKs, leavers, and people who would instantly lock my hero just to feed the entire match. I dropped all the way to Plat 5 with a 40% win rate (at this point I had about 35 hours total). Then, just as suddenly, I went from Plat 5 back to Plat 1 in like 3 hours with a 75% win rate.

The weirdest part is that I could never actually break out of Plat 1. I’d be playing against Diamonds and Masters, the games felt totally normal and we were winning, but the second I got close to ranking up, the whole cycle would just reset. I’m at 100 hours total now and this loop has happened 5 times already. Never experienced anything like this in other competitive games. Is this just a normal thing here?