This seems to happen when using “Grounding with Google search” - after multiple responses suddenly reference tags ( e.g. [1][2][3] ) will be strewn across the text, often in nonsensical places.
Like this:
And if you keep chatting in the same context, it’ll get worse and worse as the conversation goes on, and get buggy to the point of repeating paragraphs multiple times, etc.
This is only happening on Gemini 3, the only solution seems to be to branch the convo before the buggy behavior started and turn off grounding with Google.