Every account has a bad month, and the word that arrives to explain it is always the same one. It is worth separating the part that exists from the part that does not.
The part that exists
Platforms do limit how far certain content travels without removing it or telling you loudly. Instagram calls it being non-recommendable: the post stays up and your followers see it, but it is kept out of Explore and other recommendation surfaces. Reasons include content that borders on a policy line, reposted material with someone else’s watermark, and engagement-bait wording.
There is an account status page that says whether this applies to you. That is the single most useful thing to know, because it turns a rumour into a fact you can check in a minute.
The part that is folklore
- A secret ban triggered by posting too often, or not often enough
- A ban for using the same hashtags twice
- A ban you clear by taking a week off, or by posting three stories a day
- A ban that a third-party “checker” site can detect — those measure nothing you cannot see yourself
The far more common explanation
Reach is volatile. A post that reaches a lot of people gets carried by recommendations; the next one might not be picked up at all, and the drop looks dramatic because the first one was the outlier. Compare a month to a month, not a post to the best post you ever had.
One real and boring cause worth ruling out: a link, a word or an image that trips an automated filter. If several posts in a row underperform and they share a feature, remove the feature and see. That is a test; the rest is a story.