Whilst many people have opposed the decision, the navigation menu interface was forced into the WordPress Customizer.
As there are many people who don’t have to time to explain this to all existing clients, this plugin simply hides the menu panel/section from the Customizer.
The plugin is super simple (basically 1 line of CSS) and needs a minimum version of WordPress 4.3 to run as before that version the navigation menu had not yet been added to the Customizer.
There is no Settings page and we give support via Github as usual.
Credits plugin header image: Raul Petri