The epic panel on a company-managed software board shows 0 child issue count for team-managed epics

Issue Summary

The Epic panel on company-managed boards doesn't show the correct child issue counts for team-managed epics when a team-managed project is included in the board filter.

The count is always 0, even though linked child issues are returned by the filter and shown on the board.

This applies to both team-managed software projects and team-managed business projects.

This bug may be affected or solved by replacing the Epic Link field with Parent: https://community.atlassian.com/t5/Jira-Software-articles/Introducing-the-new-Parent-field-in-company-managed-projects/ba-p/2377758

Steps to Reproduce

1. Create a company-managed board (scrum or kanban with backlog configured)
2. Set the board filter to include a team-managed project that has open epics with child issues
3. View the epic panel in the backlog, and expand the team-managed epic to view the Issues and Completed counts for that epic

Expected Results

The epic panel shows accurate counts of the child issues of the epic, which match the child issues for that epic which are included in the board filter and displayed in the backlog.

Actual Results

The epic panel always shows 0 issues for that epic.

The rest of the backlog recognises the relationship, the child issues are displayed in the backlog with the correct epic lozenge and are shown or hidden as expected with the backlog is filtered by epic.

Workaround

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