Question: weather app add button is greyed out
Over the years I have been using an iPhone, I have added places to the weather app/widget, some permanently and some for only short periods - eg when I am going there for a wee while, eg on holiday. Today I tried to add my next destination, but the add/plus sign is greyed out. I've deleted the app, rebooted the phone, and added again. Still the same. I have removed the app from Widgets, saved, rebooted the phone, and added the widget. Still the same. I even tried deleting some of the older places, thinking maybe there's a limit now, but to no avail. What's happened to my weather app/widget?
iPhone SE, iOS 11.3.1