Automated mail sending problems

Hello,
I am very satisfied with Noptin, but now notice, after a few minor changes to the content of the automated email that is sent to Noptin subscribers every day at 7 a.m., that automatic sending no longer works. The sending settings are still correct. I get the message “supposed to be sent (number) minutes ago”. Manual sending works fine, the test email also works fine. I use the plugin: Post SMTP to send. I do not get an error message in the log of this plugin or in the log of Noptin.
I have now duplicated the campaign and then deleted the original campaign. Now things are going completely wrong! A campaign is now sent every few minutes, while the setting was (and is) once a day. Plugin now deactivated and removed to stop sending. How do I get this working again?

The page I need help with: [log in to see the link]