You have to customize how TB mega menu works.

In your_theme.theme you must add:

function yourtheme_js_alter(&$javascript) {
    $javascript['modules/tb_megamenu/dist/js/frontend.js']['data'] = drupal_get_path('theme', 'your theme') . '/js/frontendcustom.js';
}

?>

In your js folder of your theme you must add a custom file frontendcustom.js. The file is copied from the tbmega_menu module

You have to customise how TB Mega Menu works.

In your_theme.theme you must add:

function yourtheme_js_alter(&$javascript) {
    $javascript['modules/tb_megamenu/dist/js/frontend.js']['data'] = drupal_get_path('theme', 'your theme') . '/js/frontendcustom.js';
}

In your js folder of your theme you must add a custom file frontendcustom.js. The file is copied from the TB Mega Menu module