AppStore won’t download apps.

I’ve just purchased a new iPhone 11 Pro Max. Seems a great phone but I am having trouble getting AppStore to download apps. Once I click on the download icon, I get the spinning circle but that’s as far as it goes. No loading icon on main screen etc. I’ve tried the usual, logging in and out, switching on and off, and ensuring all details entered including payment etc but no joy. Any idea? Thanks

Gregor