Contacts on Android

When I am using the Self-Employed Android app, and creating an invoice, I go to add customer, and click on the address book icon, but only two of my contact appear.

I have attempted to save all 'Samsung' saved contacts onto my sim, my phone, and my google account and yet Quickbooks is still not finding more than one contact

Where does Quickbooks Self-Employed 'look' for contacts within an android device (filepath) and what criteria is there for a contact to appear (ie, must have email address)

Thanks in Advance

Jordan