Grid issue

Hi all and thanks in advance for any help you can provide.

Ok so I am dealing with the InventOnhandItem form. it has two tables: InventSum and InventDim as Data Sources. The original “Item name” column is a display method, but the requirement is to have it filterable. So when I try to add the InventTable (in the Data Sources) to get the Item name (no relations between tables, and set the InventTable JoinSource to InventSum with Delayed LinkType), the new InventTable.ItemName column only shows one record. The rest of the columns in the grid are the same as before and working fine. When I click on another row/item in the grid, that one row in InventTable.ItemName changes its display text to the correct Item name, but still only displaying the one column.

Any ideas on how to get the entire column to display properly?