Do you get attribution from the content they show from your sites at all? Did you notice more direct traffic by any chance?
I notice many 404s from ChatGPT to hallucinated URLs on my website. Sometimes it hallucinates guides about topics I never covered. So I'm getting cited for things I didn't even say!
I also notice that for other topics, the cited sources are crap. The best shaver is a Braun shaver according to Braun.com, and two comments on a 6 years old reddit thread about a different topic.