As per the title, I've upgraded to iOS 17 on my 2nd Gen iPhone and Standby Mode isn't working. If I plug it in (with an official Lightning charger) and put it on its side nothing happens. If I put it on its side first and then plug in the charger, I very briefly get a "Welcome to Standby Mode" message that very quickly disappears (less than a second).
I've tried both a soft and hard reset of my phone, and also switched Standby Mode off and on again. I've not tried a wipe-and-restore because it's such a faff I'd like to avoid that if possible. Searching online just gives me dozens of copy-cat articles like "15 top tips on how to get Standby Mode working" which all boil down to taking the steps I've already tried. I can't find anything specific to iPhone SE, but is there a known issue with it? If not, I guess I'll have to try the restore option.