Listboxes not appearing in data entry pages

I have 3 tables with a simplified design as:

Table1 – Companies: CompanyId, CompanyName
Table2 – Products: ProductID, ProductName, CompanyID, CategoryID
Table3 – Categories: CategoryID, CategoryName

One company can have many products
One category can have many products

I created a data projects with parent/child pages for all three tables.
I created three Project templates, one for each table.
– for Companies I created n:m relationship to Products with Categories as relation table. I can successfully edit Companies and see categories in child table.
– for Categories I created n:m relationship to Products with Companies as relation table. I can successfully edit Categories and see companies in child table.

I want to be able to edit Products table and have lookup lists for the CompanyName(stored as CompanyID) and CategoryName(stored as CategoryID). So I edited the Products project template and added two lookup listbox entries:
– CompanyID + target table=Companies with target column CompanyID
– CategoryID + target table=Categories with target column CategoryID
I edited List Table and Data Entry tabs to both show CompanyName and CategoryName in the respective lookups.
When I view the resulting project data page, the ID numbers are properly replaced by the resulting lookup text, excellent!. But if I edit one of these records, the data entry page only shows a numeric entry field, not a lookup listbox. How can I fix the data entry lookups?

Thanks!