Query via Import External Data doesn't reflect revised syntax
 

Query can be edited (a hard coded date filter) and the result is correct when
previewing (via Query Now). But after saving the query, when the query is
refreshed (via Refresh Data), the query reflects the OLD date filter.
But, if the exact same query is re-linked to Excel (via DataImport External
DataImport Data), the revised hard coded date filter is used.

How can the same query definition (xxx.dqy) have different versions based on
when it was linked to Excel?

What needs to be done to get a query that has already been linked to Excel
to use the most recent version of the syntax? (The only way I have found to
get the query to use the REVISED syntax is to add a new worksheet and relink
the query via DataImport External DataImport Data.)