Reference field on table shows sys_id instead on Display value for the table
The reference lists use the "sys_ref_list" view and it needs to be configured to show the correct columns.
- Navigate to System UI > Views.
- Search and select sys_ref_list
- In the "List" related list, search for the table you are referencing and open the record
- Go to related lists and locate the "List Elements" related list
- The elements are the columns that are displayed on the list when you click on the reference icon. You will need to add/remove as desired
- To add the desired column to the list, click new or edit an existing record
- The "Element" field value should be set to the name of the desired field. For example, if you are referencing sys_user table, you can set the user_name field as one of the columns.