You can disable it by use this function in functions.php in child theme:
// DISABLE WORDPRESS ADMIN EXCLUDE ADMIN USER
add_action('after_setup_theme', 'remove_admin_bar');
function remove_admin_bar() {
if (!current_user_can('administrator') && !is_admin()) {
show_admin_bar(false);
}
}
Code from WPBeginner.
Or you can try use third party plugin: https://wordpress.org/plugins/hide-admin-bar/.