The menus should not be touched when broadcasting pages. To diagnose, I would disable any plugins that could possibly hook into the page updating.
Which plugins are active, for example?
ACF, Advanced ACF, Child theme configurator, file manager advanced, EWWW image optimizer, Disable Gutenberg, custom post type UI, Custom 404 pro, Redirection, W3 total cache, All WPML, Yoast SEO
I’m immediately sceptical of that “child theme configurator” thing. If you disable it and broadcast, do the menus go blank?
Otherwise you can try disabling the other plugins also to see if any of them break the menu.
I disabled the plugin and still getting blank menus when after using Broadcast. It doesn’t happen every time I use so I’m trying to figure out what is triggering it, I will try to disable the other plugins as well. Thank you.