Hi Friends!

Sometimes if you want to get all post from main site into sub site. So please refer my below code.

switch_to_blog( $blog_id );
// put code for all post here.
restore_current_blog();

switch_to_blog($blog_id); = This is switch to the site in network  as per the ID.

You have added the main site id. So it will switch to the main site.

restore_current_blog(); = will restore the current blog.

I hope this article will help you 🙂