Searching for a record in a referenced table returns now results

I have a simple database that includes an Orders table and a Customers table. The Order table references the Customers table, so that when I create a new order I can link in the customers’ data. When I’m in my Orders form and I call up the search that references the Customers table, entering a search returns no results.  If I go into the Customers table and enter the same search term it always returns the correct result.

Advice welcome on how I can get the correct search result from a referenced table