Does not work as it should

Reports: "Connecting .... Connecting to the server ..." and nothing works anymore. App is not to stop or cancel (except by phone restart). Reinstalling the app helps (at least one program start long), but after that all favorites away. Had I paid money, I'd be pretty pissed. Favorites with "right addresses" you can maintain in the phone contacts, from there start navigation (Addendum below does not work either) and, if the app every time reinstalling while etc. run by the various copyright information, but that it can surely not be!

Supplement for comment by Michael Kräft (thanks for that)
did it again reinstalled: "Enable mobile data (de)" does not exist, "use Internet connection - yes or no" only. If I disable that as it is to read the "Important" in the Amazon product description below, it attaches itself as above described.
But there are other problems: I can navigate with Navigon to any of my contacts - also with the installed "Maps" work the problems. In previously been started Navigon nothing happens: he shows me just be the start menu, otherwise I get the message: "the given coordinates can not addressable".