I was thinking of a copy of the spreadsheet. Still, the image of the pivot table is OK.
For one group of the data - the top half of the table - the results are OK. The problem results are only in the bottom half of the table....
It suggests to me that the pivot table might be doing the right thing and that the data might be the source of the problem.
As in, check that all the data is what it should be. Numbers and not text, for example. Play around with the data and see if that reveals anything useful.
Again, I think some more information would be helpful.
HTH
Fazza