Reply To: Three mobile menu icons, but only one menu active for a page …

@jovito: If you don’t have any menu item in that empty menu, I can provide you with additional CSS that can hide that menu from mobile format.
Go to=> Appearance=>Customize=> Additional CSS and add the following CSS code.

#mobile-header-left-menu {
    display: none;
}
#mobile-secondary-menu {
    display: none !important;
}

Let me know if this works out!!

Kind Regards,
Sapana