Subtask panel is not displayed as expected on parent issues after migrating from Jira cloud to Jira server

Issue Summary

Subtask panel is not displayed as expected on parent issues after migrating from Jira cloud to Jira server

Steps to Reproduce

• Open Backup Manager and click on "Create backup to server"
• Use this exported backup file and restore it in the Server instance

Expected Results

All issues are restored as expected and the standard parent issue displays the subtask panel as expected

Actual Results

The subtask panel is not visible on the parent issues

Workaround

The cause of the issue has been identified to be missing "Subtask_parent_id" values for the missing subtasks in the Jira cloud database which seems to be the cause of the issue. Contact Atlassian support to confirm the issue and apply a fix for the same.