I’m able to select the widgets from my app on the simulator but they won’t appear on real devices. I already submitted my app with the widgets to the App Store and I already have that new version installed from the App Store, and still the widgets won’t appear on my iPhone. Is there some sort of setup I may be missing?
Apps unfortunately don't make it to the App Store the same day they are submitted by a user. Please give the App Store a few days to officially load the update on to your App page.
If nothing else is wrong with your setup, then it’s actually an iOS bug ever since widgets were introduced, if for any reason the widgets don't appear in widget gallery, the following steps can make it appear:
This should successfully show your app's widgets in the Widget Gallery, considering that nothing is actually setup wrong.
One thing you should make sure to check is what's the minimum version the widget target is set to. When adding a new target, it defaults to latest iOS version, but that's something you should change to your app's minimum version or iOS 14 since iOS 14 introduced Widgets.
Hope this helps.