Issue Summary

When in a Plan's Timeline page, find a Work Item that is Unassigned and try to assign it. Begin typing a name and then Jira keyboard shortcuts are trigger and prevent typing. Even disabling shortcuts results in glitchy UI and inability to type due to losing focus in field.

Steps to Reproduce

1. Go to a Plan's Timeline view, such as format: https://x.atlassian.net/jira/plans/3/scenarios/3/timeline?vid=12
2. Try to Assign a Work Item to someone by typing their name in Assignee field for the Work Item.

Expected Results

You can type a name and names will filter.

Actual Results

It is not possible to type the name and thus not possible to set Assignee.

Workaround

Possibly type the name in an external text editor and then copy to the field, until this bug is fixed.