Instagram comment automation fails quietly. There is rarely an error to read: someone comments, and nothing happens.
This is the list we work through, ordered by how often each cause is actually the one. Start at the top even if a later item feels more likely — the first two account for most cases and take a minute to check.
1. Message access is switched off
The account owner has to enable it, and no tool can do it for them:
Settings and activity → Messages and story replies → Message controls → Connected tools → Allow access to messages
If your automation has never fired once, check this before anything else. It is the single most common cause, it produces no error anywhere, and it can be switched off later by anyone with access to the account — including by an app update resetting preferences.
2. The account is not a Professional account
Comment automation requires a Professional account. Creator works up to 500,000 followers; above that, Business.
An account converted to Professional recently may also need the connection re-authorised, because the permissions granted before conversion do not cover what the automation needs.
3. The same person already triggered it on that post
Most tools deduplicate per person, per post — deliberately, so one commenter posting your keyword five times under one post does not receive five DMs.
This is the cause that most often looks like a bug during testing, because the natural way to test something is to try it again. If you are testing with your own account and the first attempt worked, the second will usually do nothing. Test on a different post, or with a different account.
Note that Instagram’s own behaviour here is inconsistent — we have measured a case where a repeat comment did fire when the documentation said it would not. So a repeat that does work is not evidence your dedupe is broken either.
4. The comment is a reply, not a top-level comment
Replies to replies usually do not trigger, and often should not: your own public reply to a comment is itself a comment, so triggering on replies can put an automation into a loop with itself.
If you need replies to count, that is normally a setting rather than a bug.
5. Your own reply triggered your own automation
Related, and worth stating separately because the symptom is different: if the automation triggers on comments from the connected account itself, it responds to its own public reply, which posts another reply, which triggers it again.
The symptom is not silence — it is a burst of activity that looks like the automation working extremely well for about thirty seconds.
6. The keyword did not match the way you expected
Two things to check:
Match mode. Whole-word matching will not fire on “PEPTIDES” if your keyword is “PEPTIDE”, and will not fire on a keyword embedded in a hashtag. Substring matching fires on both, and also on words that merely contain your keyword.
A competing automation won. If two of your active automations claim the same keyword, only one of them answers. How the winner is chosen varies by tool — some prefer the more specific target, some the older automation — so the useful thing is the symptom rather than the rule: look at what was actually sent. If the reply is copy you did not write for this automation, an older one answered instead, and the new one is working exactly as built. A forgotten automation on a single post is the usual culprit.
7. The seven-day window closed
The private reply must be sent within seven days of the comment. Comments found later — by a backfill, or after a connection outage — are outside the window and cannot be answered privately.
8. The link went out but nothing followed
This one is not a failure to fire; it is a design problem that reads like one.
If your first DM contains only a link button, the recipient tapping it does not open the messaging window, so nothing you scheduled afterwards can send. The automation did run. It simply had nowhere to go.
The fix is to make the first message’s call to action a reply or quick-reply button, and deliver the link after the tap.
Still nothing?
If items 1 and 2 are confirmed and a fresh comment from a different account on a different post still produces nothing, the problem is more likely the connection than the automation. Re-authorise the account and check whether the connection reports the specific permission the comment trigger needs, rather than just reporting “connected”.