Welcome!
This is not uncommon. It's called the "scorecard" "bucket" or "pool" problem. People are not compared to everyone else equally in scoring. Before you were in the group of people with a BK on their reports. Just before your BK aged off, you were in the top of that group and scored higher than the people who had recently filed. But now you're in the next tier up, so you start closer to the bottom of that group. The people there have had better credit for longer than you have. The good news is that so long as you pay your bills on time, don't go crazy with inquiries, etc., you can keep improving your score. Good luck!