I'm getting a signup message "400: is already a list member. Use PUT to insert or update list members."
I had a report from a client that the signup wasn't working so updated everything tested via business email. This email was originally in the mailchimp list, I manually deleted it from client's mailchimp accont. Have synced several times. It appears that once signed up and manually removed the user cannot signup again via the website?
New signups are still working fine.
Joomla 3.6.2 & CMC 3.0.0