Iphone 14 Pro - No internet while connected to wifi

This new phone is less than a week old, and this problem first reared its head last night.

I discovered that while connected to wifi, the phone cannot connect to the internet. Any app that requires an internet connection reports no internet. If I disable wifi and use only the cellular connection, everything connects to the internet just fine.

The problem was experienced on my home network. Several dozen devices were connected to the internet and had a working connection, but not my phone, even though it was connected and authenticated on my local network. "No internet".

When I came to work this morning, I experienced exactly the same problem with my office network. The phone automatically found and connected to wifi, but got the "no internet" message from my phone. Turned off wifi and the internet was fine (but, of course, I could not connect to wifi, since I had it turned off). Turning wifi back on resulted in the "no internet" advisory..

So far, I have tried rebooting the phone several times, and the problem is always replicated.

This morning, I backed up the phone (I had to use a celluar connection to do so), and perfomed a network reset. Same result. No internet if connected to wifi.

Any guidance would be appreciated.