Issue Summary

When picking up a user (any single-user picker field), sometimes a horizontal scroll will appear. If you scroll horizontally to select a user from the list, the dropdown list box will disappear, and you will not be able to select one.

Steps to Reproduce

1. In the create issue screen, move the Assignee field to the bottom of the list
2. Create a new ticket and Zoom in the browser
3. Pick the Assignee, and the user picker window appears to the right of the Assignee field, and the horizontal scroll bar will appear at the bottom of the create issue screen

Full steps please refer to: User picker custom field layout issue.mp4

Expected Results

Click the horizontal scroll bar to display the user list and select the user.
Please refer to 9_12_15.jpg for Create issue window with User picker custom field in Jira Data Center 9.12.15

Actual Results

Click the horizontal scroll bar to display the user list, and the drop-down list box disappears.
Please refer to 11.3.1.jpg for the Create issue window with User picker custom field in Jira Data Center 11.3.1.

Workaround

Please Zoom in and out on the window until the full User picker dropdown list displays to pick a user.