Around Platinum is where the Matches become random within the Tier. The beginning of the competition is mitigated, at least thus far, so Players can get some momentum. It's not a bug, you're going into the deep end. Keep trying.
My problem with this month’s battlegrounds is that it automatically forfeits and you just lose the match. This happened to me 4 times now. I still managed to reach Vibranium 2. I want to play more but it just happened to me again. It’s frustrating. Winning fights in a row and losing streak cos of some bug or whatever. You could see in the attached picture, the last two matches were forfeited after 1st round.