WordPress.org

Why is my menu Duplicated?

The Menu was probably moved using an uncommon menu hooks like

remove_action( 'genesis_after_header', 'genesis_do_nav' );
add_action( 'genesis_sidebar', 'genesis_do_nav' );

You need to change it to

remove_action( 'genesis_after_header', 'gnma_do_nav' );
add_action( 'genesis_sidebar', 'gnma_do_nav' );

How do I move the menu?

See the code in the previous question. That is the same code for moving the menu. If you want to use a different hook, change the "genesis_before_header" part of the code, if you want to move the secondary menu change "gnma_do_nav" to "gnma_do_subnav."

Alternately you can try the normal method for moving the menu, the plugin checks over a dozen of the most likely to be used hooks to see if a Genesis menu is there and then replaces it.