Bug with Series

I completed my promos with a 2-1 record, however when I won the last game I told me that I was now qualified for a series, even after I had just completed them. So now I was given a fresh promos. As you can see from my page I won 5 games in a row, while winning on average 28 LP, this put me into my promos after 4 games and the next 3 games were a win, loss, win. I then played the promos and lost both games and am still currently in platinum 5 while I should be in platinum 4.