People tend to not realize that actually a lot of their followers , are in fact, bots. Especially when you get to 5 figures.

You may no longer be doing follow/unfollow etc. But that doesn’t mean that the followers you do have are legit accounts. Many have quite possibly followed you in the same follow/unfollow manner with no actual intention of interacting with your content.

Your best bet, start going through your followers and remove the bots, the ones with suspicious looking accounts, or follows 7000 accounts etc.