The details
According to Search Engine Roundtable, the issue affected the Search performance report, the Discover report and the newer generative AI reports. Mueller said on Bluesky that Google was aware and working on it, and described it as a logging issue. Reporting was corrected going forward on August 20, and the missing data was noted as restored by August 31.
Our read
Reporting bugs like this happen a few times a year, and the timing here was unlucky because it overlapped with ranking volatility and the spam update. The lesson is to never diagnose a traffic problem from one tool. Calls, form submissions and analytics sessions tell you whether customers actually stopped arriving. In this case they had not.