Hello there,
Thanks for sharing the screenshot with us. As per the screenshot, the settings are correct and should work without any issue.
We will need to debug it more to find the issue. Can you please contact us here so that we can further look into the issue?
If you need to send the post notification manually, then I think a broadcast campaign might be helpful to you in this case. You will need to add the published post title, link into the email though. Since it is a manual process, you might need to do it every time whenever you will need to notify subscribers about a new post on the site. You can read more about broadcast campaign from here.
Hope this helps you. Let us know if you have any furhter queries.
Thank you.