How come flash messages are not propagating to the `live_component` parent?

I have an app with posts and comments, and a “Post a comment” form. The “Post a comment” form is a LiveComponent and most of the code in it has been copied from the default implementation for the way the new/update form works on default-generated index and show pages created via the phx.gen.live generator.

However, one piece of behavior that works fine with generated index/show pages is not working for the comment form and I can’t figure out why. When a user creates a new comment, this code should trigger a flash message:

      {:ok, comment} ->
        notify_parent({:comment_saved, comment})

        {:noreply,
         socket
         |> put_flash(:info, "Comment created successfully")}

but it doesn’t.

If I instead trigger a flash message in the Post show.ex file that the comment form is rendered from, it works fine. That is, this works:

  @impl true
  def handle_info({FormComponent, {:comment_saved, comment}}, socket) do
    {:noreply,
     socket
     |> stream_insert(:comments, comment)
     |> put_flash(:info, "Comment saved successfully")}
  end

But I’d rather the code for that flash message stay in the relevant form_component file.

The LiveComponent is invoked in the show.html.heex file like this:

      <.live_component
        module={FormComponent}
        id={"post-#{@post.id}-new-comment"}
        post={@post}
        current_user={@current_user}
        action={:new}
        comment={@new_comment}
      />

If there’s any other code that would be helpful to provide to help track down why this isn’t working in this case, let me know.