Standby screen frozen after 30 seconds

I have a brand new iphone 15 pro, fully updated and totally current so far as I can tell.

Since I got the phone I've been trying unsuccessfully to use standby mode, the results are always the same. The instructions, such as they are, are pretty thin and any kind of debug guide is just a repeat of the meager set up instructions.

When I turn on standby mode I set the widgets to an analog clock on the left and the weather on the right (choice doesn't seem to make much difference). It will run normally for 30 seconds or so then switch to a generic analog clock face placeholder set at 10:10:30. The left widget just goes away completely. If I long press either widget then hit done it will run again briefly and then do the same thing.

I have tried every combination of settings in the standby setup in settings, there isn't much there, checked and rechecked battery settings, power settings, tried different lock screen settings, etc. Nothing changes at all.

I'd really like to be able to use this but I'm frustrated as all get-out. I suspect that Apple had rolled out incomplete and buggy software. The typical next step is for most companies is to start working on the next thing in the pipe and this won't get better anytime soon. Call me a cynic, but looking at all the problems with this feature in this forum I'm kind of waiting for someone to tell me I'm just holding it wrong 🤪