If this is happening more recently, it is probably because Meta has surged in banning accounts following their implementation of AI to review accounts. A lot of legit accounts, some with tons of followers, have been caught up and been mistakenly banned. If you check the Instagram subreddit on Reddit, you'll see a lot of recent posts about it. One thing you could test, try posting less sensitive material for some weeks while the account is still under high scrutiny, then gradually introduce your intended content.