Update.
I waited for a call from Apple and was good, because I could understand why the app goes to a blank with apple and doens´t happen here.
In the first run I check if the language is portuguese and if is not I start in english, but I display a messagebox to advice the user how to change the language.
After the user press "OK" the app goes to a blank page.
I think that as I call a messagebox before I build the page and this function doesn´t block the app, the initial page appears but after press "OK" the app goes to a blank initial page.
I removed the messagebox.
They understand why I need the audio in background.
The app is approved now