Batch updates sent to Mailchimp get stuck in "pending" state
I'm experiencing an issue where updates are not properly syncing to MailChimp. Some pertinent details below:
- Extension is running on CiviCRM 5.29.1/Wordpress 5.5.3/PHP 7.3.22
- Sync job is being called every hour by cron, just fine.
- Mailchimp account is free tier, with a single audience being synced to a normal CiviCRM group.
- Webhook is correctly configured and receives updates from the Mailchimp side without issue.
- batch table shows all batches in
finished
status, with all having aresponse_processed
value of 0. - update table shows 172 items spread across the various batches, and for all records the
completed
column is 0 and theerror_response
column is NULL. - Sync status page shows 172 updates submitted to Mailchimp, with green Submitted flag.
- Sync status page shows "16 to add to mailChimp"
- Examining the 16 updates shows all but one are missing entirely on the mailchimp side, the one representing an unsubscribe operation. All are showing with sync status "live" and most recent update status "pending"
- The CiviCRM log has a few entries for Mailchimpsync showing where specific contacts could not be added back to the Mailchimp side because they had been previously marked "cleaned", so it does appear Mailchimp processes the queued updates at least far enough to reject those kinds of records outright.