Why did someone get my DM twice?

Steps

1. Ask the person, or look in the post’s All Comments tab: did they comment more than once? Each comment is listed on its own row.
2. Check whether they commented on two different posts. Each post’s automation answers its own comments.
3. Check whether they also sent you a DM with a keyword. A comment automation and a DM keyword automation can both answer the same person.
4. Look at what they received. A button card and then a link is one automation working as designed, not a duplicate.
5. If none of these explain it, note the username and time and email hey@instantdm.com.

Causes

What happened	Why	Can you change it?
They commented twice (or more)	Every new matching comment gets a DM and a public reply. There is no once-per-person rule for comments or story replies	No. You can only ask people to comment once
They commented on two posts	Each post has its own automation	Expected
They commented and also DMed you a keyword	Two different automations each answered	Use different trigger words, or remove one automation
They got a button card, then the link	Your Welcome Message or flow sends a button first, then the content after the tap	Expected. Turn off the Welcome Message if you want one message
They got a “Follow to unlock” card, then the link	Your follow gate is on. They followed and tapped Started following you! 👍	Expected
They got several messages in a row	Your DM Sequence has more than one message	Expected. Remove messages from the sequence
An Any Message reply came again next day	Once a day replies at most once every 24 hours	Switch to First time only
Rare: the same event answered twice	Instagram sometimes reports the same comment or message twice. For example, sharing your post to your DMs with a note can arrive twice within a second, and an Any Message reply can go out twice	No setting prevents this today

On the phone app

Home → Instagram → Posts → tap the post → Contacts tab shows each person, their comment and whether the DM was sent. For DM keyword automations, use the Contacts button on the automation card.

Good to know

• A person who comments 3 times gets 3 DMs and 3 public replies.
• First time only (for Any Message DM automations) replies once per person, ever. Once a day replies at most once every 24 hours.
• If another tool is also connected to the same Instagram account (for example ManyChat), it may answer the same people as well.

What you can’t do

• Limit comment or story-reply automations to once per person.
• Guarantee that a person is never messaged twice.

If it doesn’t work

• Many people got duplicates at the same time: email hey@instantdm.com with two or three example usernames and the time.
• See can an automation reply only once per person? for what the once-per-person options cover.