I would simplistically say that post-refers to the form, and neo-refers to the content. That is, in the case of a post-phenomenon, we see tools and methods that are characteristic of the phenomenon itself, but not necessarily the same content, and a neo-phenomenon is rather a revival or development of an existing idea with the help of new technologies.
I think that the post is something modified, and neo is something rethought.
I can't use examples to explain it, because I haven't fully understood this topic yet.
I would simplistically say that post-refers to the form, and neo-refers to the content.
That is, in the case of a post-phenomenon, we see tools and methods that are characteristic of the phenomenon itself, but not necessarily the same content, and a neo-phenomenon is rather a revival or development of an existing idea with the help of new technologies.