All of our customers are assigned a class and a location. However, some customers will only appear on reports when I customize and choose 'Location → Not Specified'. I've confirmed that there is in fact a class and a location assigned to the invoice. Then when I dig deeper and open the 'Bank Deposit' information and click on the drop-down 'Show payments for this location', I choose 'Unspecified Locations' and customer A, B or C are on there even though again, it has been confirmed there is a class and a location assigned to the invoice that was paid. 

Please help in providing information on how to resolve this issue or where it's stemming from so that I can better understand the who, what, where, whens and hows.