Missing source links in AI Mode after the Gemini 3.8 Flash release

Some AI Mode answers using Gemini 3.8 Flash appeared without source links after its September 2026 release. Google acknowledged the problem. For anyone measuring citations, the incident is a reason to record the selected model alongside the answer.

The affected AI Mode option

The selected language model helps generate the answer. Retrieval, source selection and the interface also affect the result a reader sees.

A citation here means the small link Google shows next to an AI answer saying where a claim came from. For a publisher, it gives the reader a route to the supporting page.

AI Mode is Google’s conversational tab, where you go back and forth with Google rather than scanning ten blue links. Since July, it has had a model picker: a “+” icon in the search bar that lets subscribers choose which model writes their answers. Free users get whatever Google has set as the default.

What people actually saw

Google announced Gemini 3.8 Flash on 2 September, calling it “our third Flash release in only six weeks”. Robby Stein, Google’s VP of Product for Search, said the same day it was live in AI Mode for Google AI Pro and Ultra subscribers worldwide.

The next day the screenshots started. Gagan Ghotra and Glenn Gabe both posted side-by-side comparisons on X: the same query, run through 3.8 Flash and through the default model. The default answer carried its usual set of source links.

The 3.8 Flash answer carried none. Broad, early-stage questions — the “what is X”, “best way to do Y” kind, the queries where a publisher has the most to gain — were hit hardest.

Stein replied on X, quoted by Search Engine Land: “This isn’t working as intended, and we’ll roll out a fix soon.”

What the incident shows about measurement

A change in citations can start outside the publisher’s site. Model choice and answer rendering are possible causes alongside changes to content or retrieval; the screenshots do not isolate every part of that chain.

Google is now replacing that writer every two to three weeks. Three Flash releases in six weeks, by Google’s own count. AI Mode’s picker gained 3.7 Flash in mid-August and 3.8 Flash two weeks later.

That combination breaks a lot of casual measurement. If your monthly AI-visibility report says citations dropped 30%, you cannot tell from the number alone whether you lost ground, whether the query mix moved, or whether a different model wrote the answers that month. Record the model where it is visible and compare observations taken under similar conditions. A monthly total may hide a short-lived incident.

What to do about it

Log the model with every AI Mode observation. If you are checking AI Mode manually, screenshot the picker state too. That makes later differences easier to investigate.

Measure often enough to see a step change. A drop near a model release is a lead to investigate, not proof of cause. Repeat the affected queries and compare models where possible.

Do not restructure content around a two-day bug. Nothing in the reporting suggests 3.8 Flash cited a different sort of source — it cited nothing. The reported failure does not support a particular change to schema, headings or content.