comments shortcode pulls all comments

Hm, it should only display comments from the current post, or if it’s in a loop, the current targeted post. Let me check on this, I will get back to you when I find out more.

As far as I’ve tested, the [comments] shortcode lists the comments of the current post, or for each post in the query loop.

Could you describe when it’s listing all comments from all posts? Or do you mean that you’d like a way to pull comments from a specific post, other than the current one? If so, I could add a parameter so you could do something like this: [comments id="3"] or [comments name="hello-world"].