Open Customer Center and use View menu > Re-Sort.

Run the AR Aging Summary, for Today. This confirms you have open AR by Names.

Run the Statements for Today, for Multiple Names = from that report. Use the Radio button for Date range, such as Sept 2018 to Today. Look at the options on the right, too. Preview.

If you still get No Customers, then use File menu > Utilities, Rebuild this file to relink the names to their transactions.