Created different menus for logged in users but cannot isolate main menu

Hey,
I am using the Gridbox Pro Theme and I added the following code into the functions.php to have two different menus: one for logged-in Users and one for logged-out visitors.

function my_wp_nav_menu_args( $args = '' ) {

if( is_user_logged_in() ) { 
    $args['menu'] = 'Hauptmenü_LoggedIn';
} else { 
    $args['menu'] = 'Hauptmenü_LoggedOut';
} 
    return $args;
}
add_filter( 'wp_nav_menu_args', 'my_wp_nav_menu_args' );

This code solves my main issue of having two different menus, but it automatically transfers the footer menu as well. I thus need an improvement for isolating this if-clause for only the main menu on top.

Note: I already tried to get an answer from a different question in this forum, but the suggested solution doesn’t work on my project. Here is this code:

/* Menu for logged in and out users */
function prefix_main_menu_location() {

	$return = 'main_menu';

	if( is_user_logged_in() ) { 
		$return = 'logged_in';
	} else {
		$return = 'logged_out';
	}

	return $return;

}
add_filter( 'ocean_main_menu_location', 'prefix_main_menu_location' );

Thanks for the help and stay healthy.