Sometimes the map dosen't show up. Also, did you change invincibility frames for the dodge? I hope not, because it's way more fun to dodge attacks by moving your hitbox away from the attacks.
Must've been because I was using the hotdog. Stopped using it. In any case, Rein was a fun and hard fight, and it's nothing a Silksong fan can't handle. I hope the next chapters (if there's more than two chapters) has similar difficulty.