When we enable customer registration on My Account page, We will know that when new user is register it’s automatically logged in .
it need to change when we need to manually approve each user.
In that case we have to stop this Programmatically.
we can simply use 'woocommerce_registration_auth_new_customer' filter for that.

add_filter( 'woocommerce_registration_auth_new_customer', '__return_false' );
Enjoy