WAIT: Mailchimp sign up only works with double opt-in turned on

Browser: Chrome 110
OS: macOS / Windows / Linux / etc.
URL: https://oend.instawp.co/about/

I’m attempting to use the Mailchimp action on a form. When I have double opt-in turned off on both the form and in my audience settings, the form’s error state is triggered on submit.

If I turn on double opt-in in just the form settings (but not Mailchimp), I get a success message but nothing posts to my Mailchimp account (which is expected).

If I turn on double opt-in on both the form settings and in my Mailchimp account, the form submit is successful and the double opt-in process in Mailchimp is triggered.

However, I don’t want to use double opt-in for this audience, I only want to use single opt-in and I can’t figure out why the form isn’t submitting with single opt-in.

A few other notes:

  • I’m testing this on a fresh site without any plugins so I can confirm that there aren’t any conflicts
  • I do not believe that this is an API issue because I can successfully get the form to submit with double opt-in is turned on on both the form settings and the audience.
  • Nothing gets logged in the console so I can’t tell what the error is

Hi Tory,
Thanks for your report, and sorry for the late response!

Please test the form with single opt-in using an email address that has never previously been added to or unsubscribed from this Mailchimp audience.

If that address also fails, please send the response shown for the form submission request under your browser’s DevTools > Network panel. That response should expose the Mailchimp error even when nothing appears in the console.