Notification not sent when a new Jira event is added to a Team Calendar on a watched calendar

Issue Summary

Email notifications are not sent by Confluence when a new Jira event is added to a watched Team Calendar.

Environment:

• Confluence DC 7.13.0
• Team Calendar 7.1.4
• Jira 8.18.1

This is reproducible on Data Center: Yes

Steps to Reproduce

1. Set up a mail server within Confluence.
2. Integrate Confluence with Jira via app link.
3. Create a project within Jira.
4. Create a Team Calendar within Confluence.
   1. Configure a Jira Issue Dates event type within the calendar.
   2. Either select a project in Jira or use JQL to select a project.
   3. Select a single date type that will be used to display a given Jira issue within the calendar.
5. Set yourself as a calendar watcher.
6. Create a new issue within the appropriate project in Jira.

Expected Results

1. The new issue should appear in the Team Calendar that's embedded within the Confluence page.
2. Confluence should send an email notification to the Calendar watcher since a new event appears within the calendar.

Actual Results

1. The new Jira event does render within the embedded Team Calendar
2. However, no email notification is sent for this new event addition to the Team Calendar

• No errors are displayed within the mail queue.
• No errors are recorded within the Confluence logs (even with notification debug logging enabled).

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available.