iPhone 12 mini not downloading new apps

Hey, I’m struggling to download new apps. I’ve checked/updated my credit & debit card details, checked my IOS is up to date, I’ve signed out and signed in again, I’ve switched my phone off and on, and it’s just not working. If I download an app on my old phone I can then access it from the App Store, I can access all my old apps etc, just can’t download anything new… any suggestions?