Data Range for a Pivot Table won't stay put

I have a pivot table that I have been using for eight years. Just this year it started randomly losing the range settings for the data. I have a range prescribed that's something like $A$2:$X$1000. Once in a while I'll go to refresh the pivot table and nothing happens. Then when I check the range it's changed to something like $A$7:$X$7, or sometimes it's row 8 instead of 7. There's nothing special about those rows, and there's nothing different about the data in the table from previous years - it's the same dang types of numbers, just for a different year.

Does this sound familiar? I can't attach a sample because it contains sensitive data.