iPhone 14 notification problems

I’m notification problems on a brand new iPhone 14 pro iOS 16.0.2. No notification sounds at all on many apps. eg news sources not only 3rd party but Apple apps as well. No notifications at all on many apps. sound or otherwise. Some sound notifications sometimes on some apps. Rarely know of a new notification unless I physically check the Notification Centre. Whole phone figured correctly. Apple Genius Bar checked all settings, rebooted etc. etc. and failed to solve the problem. Two and a half hours on the phone with Apple Support working long and hard but also failed to solve the problem. None of the fixes suggested on this thread, by Apple or anywhere else have worked for me. Is it a software problem or could it be a hardware problem with the phone itself? I’m not happy.