I have designed a pivot table that I intended to update each month.
My data table includes a column for the date at the monthly level.
Until this month, it was working fine.  As each month passed, I would
simply check off the new month in the drop down menu in the pivot
table.

However, for some reason, when I select November, the table does not
expand one column.  Instead, the table stays the same size, but drops
March data (though March remains selected in the drop down).

I've never come across this before.  Any ideas what I'm doing wrong?
Thanks!