Why is excel pivot suddenly adding extra columns to my report? 😡

CarmelPeinke 

First of all, calm down. You may not want to hear it, but Excel is doing what it's programmed to do; you haven't been the victim of something that the Excel demons have decided to visit on you. Far more likely is the probability that you unwittingly have shot yourself in the foot, perhaps with Excel handing you the instrument to carry that out.

From your description, my first guess as to cause would be that you made a change in the array of raw data that this pivot table is summarizing. That would also be my second and third guesses. They may be rows or columns that you've hidden in that raw data, but rows and columns that aren't hidden from Excel.