FrameMaker: Update cross-references to imported spreadsheet

Greetings.

I'm importing by reference an Excel file into a FrameMaker file.

I'm then cross-referencing from this FM file to multiple other FM files to generate multiple price sheets. At least that's what I'm trying to do.

When I update the excel file, the importing FM file also updates as expected. However, the cross-referencing FM file does not update. Instead, the cross-references become unresolved. When I try to reestablish the cross-references (select the file, click Open), the error just reappears.

I'm looking for a way to maintain these cross-references from a live import file. (There are thousands of prices to update. The screenshots below are a micro sample I'm using to experiment on.)

Here are the importing and x-ref files before I update the spreadsheet:

Here they are after I update the spreadsheet: