Hello,
I am using an add-on in SP Pagebuilder "Opt-in Form" for ACY Mailing.
When I enter an email address that already exists, nothing happens,
There is a circle spinning, and it keeps on spinning, and spinning, and spinning and......
I have asked ACYmailing for support, and they reply:
... I can tell you, as far as I know, they have this form ready for version 5 of AcyMailing. They don't have version 7 compatible form. In that case, you really have to contact their developers and ask for the update of this form to include version 7 compatibility.

So, can you help me with this?