A Google AdWords representative confirmed a bug in a Google AdWords Help thread where Google AdWords professionals with MCC (My Client Center) accounts are not all seeing data for their clients.
Reportedly, some are seeing zeros in the reports for their clients.
Adwords representative Bindu said:
Some MCC accounts in the last 90 day show spend as zero in their Professional Qualification accounts. This issue has been escalated to our engineers who�re working to resolve this on high priority. Please be assured that all the account affected will not lose their qualification and the correct spend will be updated soon.
So it is good to know that qualifications won't be impacted but it might be hard to manage client accounts when the data is half missing.
Of course, Google understands this and I am sure they are working hard to fix it.
Forum discussion at Google AdWords Help.