Filters should not use the assignee values as suggested values for custom user fields

Issue Summary

The Team Managed JWM project's board filter is not showing the complete list of users when the Assignee field is not added to any issue type in the project

Steps to Reproduce

1. Go to a Business Team Managed project.
2. Remove the assignee field from all issue types
3. Create a People field (single-user picker)
4. Go to the projects' board
5. Go to the custom field filter section in the Filters menu

Expected Results

Show the list of users to filter the board with.

Actual Results

The filter only shows the users that currently have an issue assigned and the "Unassigned" value OR if no assignees in the project then it will only show the "Unassigned" value

Workaround

If the assignee field is not being used, then add it to an issue type in the "Hide when empty section"

1. Go to Project Settings
2. Issue Types
3. From the left column, drag and drop the "Assignee" field into the "HIDE WHEN EMPTY" section.

Reference: