Facebook has fixed the related Insights API bug.
Things should be back to normal now.
Thanks for your patience!
Posted Feb 09, 2015 - 15:37 CET
Identified
Since february 1st, Facebook has a bug that impacts our platform : Facebook Insights APIs do not return the correct fan count for some pages.
It affects Agorapulse reports and subscriptions.
Here is the detailed Facebook bug: https://developers.facebook.com/bugs/450861968399907/ "Facebook engineering was able to identify the issue and start the recovery process. However, due to the amount of data, full recovery will take up to a week."
So we hope that the issue will be solved soon, sorry for the inconvenience.