I'm going to try to break this down as best I can. My company has a Python based application that runs a connection to Adwords API. In one of many places that I request a Campaign Performance Report, as of around Nov 30th (bug reported then), our application started experiencing some odd behavior.
We request Clicks, Cost, Impressions, Conversions, AllConversions, SearchImpressionShare, SearchBudgetLostImpressionShare, AverageCpm, SearchRankLostImpressionShare, Amount, Ctr, AverageCpc, AveragePosition, CostPerConversion, ConversionRate, SearchRankLostImpressionShare all at the same time. The attributes are CampaignStatus and CampaignName. The segments are AdnetworkType1 and Device. AdnetworkType1 is filtered by Search Network.
Requesting the same data from the same set of campaigns for the same time period (meaning just refreshing the page) will give me different results. Most of the time I get all of the data EXCEPT I get all 0's for the cost. Every once in a while I will get the cost that is actually displayed in the Adwords front end.
I am very confused by this because the same code is being run each time and in fact this section of code has not changed in many months.