Instagram DM automation unstable after 2–3 messages (ManyChat + Make webhook) – synchronous issue?

 Instagram DM automation unstable after 2–3 messages (ManyChat + Make webhook) – synchronous issue?

Hello,

I’m currently building an Instagram DM AI agent using ManyChat connected to Make (webhook + OpenAI), and I’m facing a persistent issue on multi-message conversations.

🔧 Setup

• Trigger: User sends a Direct Message (Default Reply – set to “every time”)
• Flow:
  1. External Request → Make webhook
  2. Make processes message (OpenAI + routing)
  3. Make returns JSON:
     {"reply":"<text>"}
  4. Response mapping: $.reply → custom field (make_reply)
  5. Instagram Send Message → {{make_reply}}

❗ Problem

• First message → works perfectly
• Second message → usually works
• Third message → becomes unstable:
  • Sometimes the webhook is not triggered
  • Sometimes Make does not receive the message
  • Sometimes the reply is delayed or corresponds to the previous message
  • Sometimes no Airtable record is created

🔍 Observations

• The automation is triggered every time (confirmed in ManyChat logs)
• last_text_input is correct
• The flow continues after External Request
• The custom field make_reply is updated
• BUT:
  • The message sent often corresponds to the previous value of make_reply
  • Or the webhook is not triggered consistently after multiple messages

✅ Already tested / ruled out

• Default Reply trigger configuration (set to “every time”)
• Instagram connection / permissions (refreshed successfully)
• No duplicate automations / no keyword conflicts
• No Meta Inbox / routing conflict
• Webhook format and JSON response are correct
• Airtable / OpenAI / Make routing all working independently
• Simplified body: {"message":"{{last_text_input}}"}

🧠 Hypothesis

This seems like a synchronous limitation between ManyChat and the External Request:

• ManyChat waits for the webhook response
• On multi-turn conversations, timing becomes unstable
• Result:
  • outdated custom field values
  • missed webhook triggers
  • inconsistent replies

❓ Question

Has anyone experienced instability with External Request + multi-message Instagram conversations?

Is this a known limitation of synchronous webhook handling in ManyChat?

👉 Would switching to an asynchronous architecture (Make → set custom field → trigger separate response flow) be the recommended approach for stability?

Any insight or confirmation would be greatly appreciated 🙏

Aidalis