Hi, I have the same problem.
I have users who have changed their email addresses within WordPress …. but the mailpoet lists still use the old address.
I’ve tried force syncing but this does nothing.
I tried to edit the users entry in the list, as above, but also have the users email, first, last name all greyed out and uneditable.
In the lists drop down it does not show the WordPress Users list.
I did delete a user from the wordpress users list ( from viewing his name in subscribers – not by deleting them from WP ). But now I am unable to get them back into the list.
I note that there is an entry using the new email address in the Woocommerce list – but I have no idea how to move that to the WordPress list. I do not use the Woocommerce list at all. I just use segments of the WordPress list. Or would if they worked properly.
All a bit frustrating just to try and send an email to all my members!