As you’re using _x() as your translation function you should do one of the following.
1) If 'slug' is supposed to be your text-domain, add context to the _x() functions, e.g. _x( 'Homepage', 'page title', 'slug' ).
2) If 'slug' is your context, then add the text-domain, the third parameter, to your translation functions as the text strings you have don’t seem to be default texts and most likely won’t be found in the default text-domain.
3) Switch to using for example __() or esc_html__() translation function, which only needs stringand text-domain as parameters.