I don't know if im on the right forum but i think someone did something weird on my instagram

[sweetestgirlintown]

there is this user on instagram who has not blocked nor restrained me, and I don't know why, every time I try to look for her user in someone's "followers" or "following" list, she does not appear. Like if I pick a random person on her follower list (I know they follow her) and go to their profile and look up her username, she doesn't show up on their "following" list. I need to know if this was done on purpose with some computer hack or if it's like a mistake. I know she's friends with someone who studied computer science.