Mailchimp Pop form is not showing on my site

Are you using MC4WP and Boxzila to create this popup?
https://www.mc4wp.com/kb/pop-up-integration/

Or is it a different type of Mailchimp popup?

I have same issue. ..

I use MC4WP and mailchimp to create… It says it’s connected, but when I try to establish test fail (406)

MC4WP does not offer a pop-up by itself. Only if you combine it with our other plugin, Boxzilla you get a popup option, please see: https://www.mc4wp.com/kb/get-email-notification-every-sign-up/

If you created a popup from the Mailchimp .com system, that is separate from our plugin, and for support with that you would need to contact Mailchimp support.

Hope that helps. If you have any questions, please let me know!