A variable field in the variable editor shows as empty (no data entered), but the data that was entered for the variable is actually saved.
Issuing g_form.getValue('duplicate_var_name') returns the non-empty saved value, but no value is displayed in the variable field.
This may be caused by using an order guide, and the same variable name in different variable sets within a catalog item.
The empty variable field in the submitted RITM record corresponds to the variable that was not used while filling out the order guide. The other variable, with the same name, is being queried with g_form.getValue('duplicate_var_name') when debugging and returning a value. But this second variable is not being displayed in the variable editor giving rise to the confusion.
Rename all variable names so they are unique, even when they are placed inside different variable sets for the associated catalog item.
This issue may also manifest after upgrading to London.