Google has confirmed that impressions were undercounted in the Search Console report covering Generative AI performance for data from November 9 through November 11, 2026. The company posted the notice on its data anomalies page, stating that the issue “affects data logging only.”
Search Console now shows an annotation on the report marking the affected dates. Barry Schwartz of Search Engine Roundtable noted that the November 2026 core update began on November 10, inside the same window. That overlap is the practical risk. A team comparing AI-feature impressions before and after the update could read the dip as a ranking loss when it is a measurement artifact.
Per Google’s notice and Schwartz’s report, the problem sits in reporting, not in how pages performed in Google Search. Google has not said whether the missing impressions will be backfilled.
Anyone building a before-and-after view of the core update should mark November 9 to 11 as unreliable in that AI report and judge AI-surface visibility only from clean dates on either side.
Search Engine Roundtable, Barry Schwartz, November 12, 2026.
