I ended the season Dia. 3, Dia, 5, and Mas. 4 in Tank, Dps, and Support, respectively.
When season 3 ended it lowered all my ranks by an exact ENTIRE rank, so it said I ended Plat 2, Plat 4, and Dia 4, and then gave me my rank rewards. So I got diamond as my highest rank when I was supposed to get master rank rewards.
I thought rank decay was supposed to be gone?
it has happened to all of us who logged in the first hours of the game, and to other people up or down because now the rank depends on the general MMR, but if you started the first hours of season 4 sure your rank is quite low because of an error.
You are not alone in experiencing this bug. Here is a link to my post in case you would like to read more about this issue: Comprehensive Thread Of All Top 500/Competitive Bugs. I’ve compiled a list of posts regarding similar bugs under: Incorrect Rank Adjustment. Please help in spreading the word about this megathread and other related threads, we must demand the Developers to give us the rewards we rightfully earned.