Incorrect result in subscription email using search filter with JQL issueFunction in addedAfterSprintStart()

The JQL function addedAfterSprintStart() returns different result in the filter subscription email. It seems to also include the issues added to the sprint before it commenced. The same saved search filter, however, retrieved the correct set of issues in the Issue Navigator.

Steps to Reproduce the Problem

Prerequisites

• Ensure that the Outgoing mail is configured & enabled
• Create a sample Scrum software development project
• Create an Agile board (Scrum) in the project

1. On the top navigation bar, click on Projects & select the sample project
2. On the left sidebar, click on Backlog
3. At the Backlog section, click on + Create issue > input any value as Issue Summary > hit Enter
4. Repeat step 3 two more times to create 3 issues
5. Click on the Create sprint button on the right > select any Start Date & End Date > click Create
6. Drag the 3 created issues into the sprint > click Start sprint
7. Repeat step 3 & create another 3 new issues
8. While the sprint is now active, drag the 3 newly created issues into the sprint
9. On the top navigation bar, click on Issues & Search for issues
10. In the JQL search bar, input either of the following queries

    issueFunction in AddedAfterSprintStart("Board Name")

    issueFunction in AddedAfterSprintStart("Board Name", "Sprint Name")

11. Hit the Search button > click on Save as > input the Filter Name > Save
12. Click on the Details link > click on New subscription > Subscribe > Click on Details again > Manage subscriptions > click Run now to send the subscription mail
13. Compare the issues listed in the subscription mail with those that are returned via the Issue Navigator. Subscription mail: 6 issues vs. Issue Navigator: 3 issues

Expected Behaviour

In the filter subscription email, the JQL function returns only the issues that are added after the sprint starts.

Actual Behaviour

In the filter subscription email, the JQL function returns issues that are added to the sprint before it starts.

Additional Info

• Reproduced in
  Jira Software 8.13.8 | ScriptRunner 6.17.0
  Jira Software 8.13.8 | ScriptRunner 6.41.0