Lots of apps don't load on iPhone, even access to Appstore doesn't work

Hi, I have an iPhone 14, IOS 17.0.3, and I use 4G or a wifi-connection. I can make phone calls with my iPhone, check and receive mails and send text messages. So there's a connection with the internet. But apps like Spotify, Waze, Instagram, Banking apps and so on will not load. Even the Appstore will not load. When I try to search for an update of the IOS I get the message that searching for updates failed. I took out the SIM-card and put it in my iPhone 11. The problem remained on my old iPhone. So I thought there was a problem with my SIM-card. I called my provider. He said that there's no problem with the connection on their side. I can check my mails so that could be correct. I've already switched of and on my iPhone 14 several times. I connected my iPhone to my Macbook to put back a back-up from iCloud, but the button to start that proces is inaccessible. Who can help me with this issue? Sincerely.