User avatar-ACF fields

I'm running wp multisite and using ACF custom field (user edit) for my local avatar, in my functions.php i added :

add_action('get_avatar', 'tsm_acf_profile_avatar', 10, 3);
function tsm_acf_profile_avatar( $avatar, $id_or_email, $size, $default, $alt ) {

$user = '';

// Get user by id or email
if ( is_numeric( $id_or_email ) ) {

    $id   = (int) $id_or_email;
    $user = get_user_by( 'id' , $id );


} elseif ( is_object( $id_or_email ) ) {

    if ( ! empty( $id_or_email-user_id ) ) {
        $id   = (int) $id_or_email-user_id;
        $user = get_user_by( 'id' , $id );
    }

} else {
    $user = get_user_by( 'email', $id_or_email );
}

if ( ! $user ) {
    return $avatar;
}

// Get the user id
$user_id = $user-ID;

// Get the file id
$image_id = get_user_meta($user_id, 'avatar', true); // CHANGE TO YOUR FIELD NAME

// Bail if we don't have a local avatar
if ( ! $image_id ) {
    return $avatar;
}

// Get the file size
$image_url  = wp_get_attachment_image_src( $image_id, 'thumbnail' ); // Set image size by name
// Get the file url
$avatar_url = $image_url[0];
// Get the img markup
$avatar = 'img alt="' . $alt . '" src="' . $avatar_url . '" class="avatar avatar-' . $size . '" height="' . $size . '" width="' . $size . '"/';

// Return our new avatar
return $avatar;
 }

This works great on main blog (blog 1), but problem is when i add that users on subsite(blog 2), my avatar field is empty in blog 2, also after that, if I upload avatar on blog 2, then same user on blog 1 get some random image of some random user.

I have no clue why this is happening, any help is welcome.

Thank you