wp query – Multisite – how to stop rewriting and redirecting to wrong locations?

How can I stop my wordpress multisite from rewriting my URLs from:

/news/?paged=20

to

/news/page/20/

I have this set up in my functions.php

function add_query_vars_filter( $vars ) {
  $vars() = 'paged'; // variable for pagination.
  $vars() = 'p'; // variable page for pagination.
  return $vars;
}
add_filter('query_vars', 'add_query_vars_filter');

And I have no ideas why WordPress keeps rewriting my URLs.

Sometimes, it just redirects to:

/en/hello-world/

That is completely wrong!

Any ideas?