Drop Down Search Field - Mystery

I have a datagrid displaying several attributes. One of these attributes is from an associated entity - lets say that the datagrid is orders and the associated entity is customer In the datagrid, customer name is displayed with no problem When I add a Comparison search field to the datagrid pointing to Customer Name, I can successfully search using part or all of the customer name. However, when I add a drop down search field to the datagrid pointing to Customer Name, there are no values in the drop down. I have tried several different things to resolve this, and can't seem to figure it out. Hopefully, someone in the forum will be able to spot my (stupid) error.
1 answers

You probably did, but did you check the entity access rules?

Customer is not a specialization of User/Account? If it is, did you enable the correct userroles under User Management (Project Security > Userroles)? The userrole you are using needs to be able to 'Manage' the customer userrole in order to be able to view the information in reference dropdowns.