Earlier quoted context omitted.
I don't think that you are right. It is the search result that influence the llm generated result and not the opposite. In your case, I think that it is just the interrogation point in itself at the end that somehow has an impact on the results you see.
It’s a feature of Kagi. Putting the question mark does invoke AI summaries. https://help.kagi.com/kagi/ai/quick-answer.html
What I say is that the search results part of the page, with or without the summary should be the same in theory.
So if the other person saw a difference in the result returned it might be only because of the impact of the question mark character itself on the search index