I finnished s1 last act and was matched against plat/low dia this act for some reason, won 1/5 placement games and got plat 2. what the fuk, can somebody explain?

One of the first chibis I've made for the agents but never uploaded it on reddit. Was the first time I wanted to take my art seriously and a lot of people liked it! It's probably my fav one too :) https://preview.redd.it/okbp1jjcofya1.jpg?...