Branch Parenting Issue

A few months ago I restored a backed-up branch for a borked migration from a different server. I now have created my "main" branch from this backed-up branch and is currently using it on production. As of now, my branch naming's are kind of messed up and I want to clean it up. My issue here is that, my "main" branch parent is from "main_backup", and that one has a parent of "main_old_2024-xxxx". I am unable to delete this "main_old_2024-xxxx" branch due to this parenting issue. Is there a way to reset this hierarchy and have all of the branches deleted without touching the "main" branch?