I'm beating all the people, but on the end screen, it says I have one defeat, and same with the overview of the group, which makes me not able to rank up. I'm leading with 6/7 anyways, so it's not a huge deal, but yeah.

Hi, it's possible that server simulation (results that are actually used for league promotions) sometimes slightly differs from the local simulation (replays you see) leading to situations like this.
That has been happening more often with the just ended Blind Fight season's mod, likely because it was using environment objects that were causing a bit too much randomness.

We'll be looking into ways to improve consistency between simulations but for now there's not much that can be done about it - though hopefully it will be a bit more reliable this season as it uses a slightly simpler mod.