You can make any field the Primary. You have control of this designation.
This is not an Issue so I am changing it to question for forum consistency. The forum category Issue should be used when something is broken or clearly not working as intended in Samba not to be confused with configuration errors.
the entire thing is fully custom. Customers was just setup as sample data you in fact can make it anything you want including the screen. play around with it you will get familiar with it quick through trial and error