Jira Issue Assignee is cleared when the issue is committed from Portfolio

Summary

Jira Issue Assignee is cleared when the issue is committed from Portfolio

Environment

Portfolio 2.13.0

Steps to Reproduce

1. Have an Initiative in Portfolio, which has a Epic and then story under it.
2. Make sure that the Initiative, Epic and Story have assignee in Jira side.
3. Reprioritizes the Initiative. Eg: More this Initiative to the top of the scope table.

Expected Results

No change in Jira side to the assignee

Actual Results

Assignee is cleared in Jira side

Notes

This happens to any issue committed from Portfolio side, where Portfolio clears the assignee.