is_network_admin() function does not work correctly on multisite

[stefanowp2021]

I'm trying to execute this simple function on a wordpress 6.0 multisite:

function network_admin_check() {
    
    if ( is_network_admin() ) {
        echo __( 'You are viewing a WordPress network administration page', 'textdomain' );
    } else {
        echo __( 'You are not viewing a WordPress network administration page', 'textdomain' );
    }
      
}

add_action( 'admin_init', 'network_admin_check');

Reference: ​https://developer.wordpress.org/reference/functions/is_network_admin/

It partially works. I want to show a message when I'm in website.com/wp-admin/network/ but it only works on the else condition, example when I'm in a subsite backend like website.com/de/wp-admin it shows the message "You are not viewing a WordPress network administration page".

[johnbillion]

Thanks for the report @stefanowp2021 and welcome to WordPress Trac. I'm unable to reproduce this problem on a fresh installation of WordPress Multisite. The is_network_admin() function is working as expected in the network admin area.

Can you confirm whether the problem persists if you deactivate your plugins and switch to a default theme such as Twenty Twenty One? Don't forget to check for any plugins in wp-content/mu-plugins or a wp-content/sunrise.php file too.

[stefanowp2021]

Replying to johnbillion:

Thanks for the report @stefanowp2021 and welcome to WordPress Trac. I'm unable to reproduce this problem on a fresh installation of WordPress Multisite. The is_network_admin() function is working as expected in the network admin area.

Can you confirm whether the problem persists if you deactivate your plugins and switch to a default theme such as Twenty Twenty One? Don't forget to check for any plugins in wp-content/mu-plugins or a wp-content/sunrise.php file too.

Hi John,
I've tried on another wordpress installation and it works ok for me too.
I need to investigate further to fix the issue.
We can close this ticket considering is not a wordpress bug. Thank you.

[johnbillion]

Thanks for letting us know 👍