Unable to assign users from different patron groups

1. Go to any environment
2. Assign several users from the same patron group to a set of KB credentials
3. Attempt to assign a user from a different patron group to the same set of KB credentials

Expected outcome: Any user assigned to any patron group OR not should be assigned to a set of KB credentials

Actual outcome: Unable to assign users from different patron groups to a set of KB credentials

Screenshot - users with the same patron group assigned to a set of KB credentials

Attempting to assign a user with a different patron group to the same set of KB credentials