When you press the button to create multilanguage infraestructure with KMFasTrans, a menu titled 'Menu All' is created with a menu item titled 'Menu Item-All' which is the default Home Page for language 'All'. If the plugin 'System - Language Filter' is disabled, when changing language the user is always redirected to the default Home Page menu item for the language 'All' whose title is 'Menu Item-All'.

The problem is solved by enabling the plugin 'System - Language Filter'.