Thank you for your post.
First make sure your menu is synced,
Go to Appearance >> Menues
and Create menus in the other language
Go to WPML >> WP menus Sync
and sync your menus.
Please go to Dashboard >> WPML >> Languages
Go to Language switcher options
find Language switcher in the WP Menu
Mark the little box and choose your menu
and select flag
Hope this helped