Primary Menu don't disapear when selecting adding other Top Header Menu

Hi! I created a new Menu and selected the option to put it as Top Header Menu. The other Menu (the default one, with "Home") is not selected in the , nor the Secondary Menu. I edited the options at Dashboard -> Appearance -> Customize -> Menus -> "My Menu" -> Menu Location, but still, I have the Primary Menu showing too. So I ended up with a duplicated Menu. For some reason the primary default Menu is always there, except if I change the location of "my menu" to Primary. Then it substitutes it. But I want "my menu" to be on the Top Header. Did I miss something in the process? What can I do to make the default menu disappear?