Strange IG problem

I'm having a strange problem with my IG.

Up until the last 2 weeks I've been sailing along with 150-200 followers a day up until 90,000. However, since then it has dropped to 30 a day. I am not doing anything different, engagement has dipped ever so slightly but not hugely.

I am getting notifications of the same people following 3 times in a row and also, for example, I login to see 20 or so new followers and then I check my insights and the follower count has only gone up by 2 people.

I have never botted so I am a bit puzzled as to why this is happening.

I'm still reaching all the hashtags too

Maybe the audience in you niche is limited, you may try finding people relatable to your niche or in other demographics

Increase account activity (more posts) and make sure hashtags are properly optimized.

May I inquire your niche?

There is only 1 bigger account than me in my niche and they have 50k more followers so I don't think it could be that.

Anyone have any other suggestions?

I am also getting notifcations of being tagged in posts that happened 2 months prior. I've got 3 photos in the top of a 2.3m hashtag so it's definitely not a ban