Hello,

I am experiencing a problem in notifications of new comments to users.

The problem is that sometimes users do not receive the notifications in their mailbox.

After doing dozens of tests, we have come to the conclusion that the problem is that the execution of the action "wpdCheckNotificationType" depends on the user.

When a user submits a comment, the "wpdAddComment" action is executed first and if successful, then the "wpdCheckNotificationType" action is executed. These actions are executed with an Ajax call which I believe is in the wpdiscuz.js file in the getAjaxObj function.

What is the problem? If you have a large number of subscribers (2K or 3K) the script can take several minutes to execute, and if the user exits the page or closes the browser, this script doesn't seem to finish executing.

In the two tests performed, in a comment with 160 subscribers only 27 notifications have been sent and in another test, with 274 subscribers it has been sent to 257.

This could be solved in two ways:
1. Saving the notifications to be sent in a table and the wp_cron would send them in blocks.
2. Using the Beacon API of javascript so that the sending would not be cancelled when leaving the page.

This second solution could be as simple as substituting this:

[I attach an image with the suggested code change because Wordfence blocks me].

This would allow calls to actions not to be cancelled halfway through.

Yours sincerely,
Luis