Why does a pivot table reset when changing external connection source?

[pbannan]

My pivot tables are completely resetting when changing external connections, even when the data structures are identical. It works fine for data within the workbook, but external connections. From what I've researched I should be able to do this without completely rebuilding my pivot tables. Am I missing a step? Is there a workaround?

[#2]

May I know what external connection you are using? SQL server?

[#3]

@pbannan 

I guess that happens if you add data to data model. With changing PivotTable data source (connection) old tables are removed from data model and new one are added. Even if they have the same names and structure.