Google confirms Search Console AI report undercounted impressions November 9 to 11

Google has confirmed a logging bug in the Search Console Generative AI performance report in Search. It lowered the impressions recorded for November 9 to November 11, 2026. Search Engine Roundtable reported the confirmation, which Google posted on its data anomalies page.

What Google said

• The notice reads: "A logging error caused a decrease in impressions on the Generative AI performance report in Search for data from November 9 - November 11, 2026. This issue affects data logging only."

• The report now shows an annotation on those dates.

• Search Engine Roundtable says the bug had no impact on performance in Google Search. The drop is in the reporting.

Why this window is hard to read

The November 2026 core update started on November 10, 2026, while the bug was still running. So a dip in AI impressions across those days mixes two things: a known undercount, and whatever the core update did to your pages. The report cannot separate them for you.

That matters more here than anywhere else in Search Console. The Generative AI report is one of the few first-party views of how often a site appears in AI Overviews and AI Mode. It shows impressions only, with no clicks and no query data, so nothing else in the report lets you cross-check a drop.

What the source does not say

• How large the undercount was.

• Whether Google will restore the affected days. The notice says nothing about it.

• Whether the overall Performance report is affected, even though its totals have always included AI impressions.

• Whether the Generative AI report for Discover was hit. The notice names the Search report only.

What to do with it

• Annotate November 9 to November 11 in any client report or dashboard that pulls from this report, so nobody reads the dip as lost AI visibility.

• Use October as the baseline when you judge AI impressions this month. A comparison that starts inside the bug window starts from a broken number.

• Judge the core update on clicks and rankings first, since the notice does not name them as affected. Come back to the AI slice once you have clean days after the bug.

• If a client asks why their AI impressions fell last week, tell them straight: this report alone cannot answer that yet, and anyone who claims it can is guessing.