Modern LLM offerings can use tools, including search, and that (like most good RAG) enables citation and fact checking. If you use LLMs like it's late 2022 and you just opened ChatGPT, then that's not indicative on how you should be using LLMs today.
I think I cleared my point about tools in another reply I wrote somewhere close [0].
As I said, the network doesn't carry citation/source information. IOW, when it doesn't use a tool, it can't know where it ingested that particular piece of information.
This is a big no no, and it's the same reason they hallucinate and they'll continue doing that.
As a tangent, I see AI agents hit my digital garden for technical notes, and I'll probably add Anubis in front of that link in short order.