I've added a handful of settings to my widget in properties.xml. They show up just fine in the App Settings Editor:
The widget reads the settings just fine in the emulator, both for default and altered values, and when deployed to my Vivoactive 3, the widget runs fine, showing all the behavior I'd expect with the default values (including pulling data from the default URL, which is only ever defined as a setting default). However, neither the Garmin Connect app nor Garmin Express show any way to configure the widget once it's deployed to the device:
Is there something I'm missing in my XML? The whole project folder is available on my Github page, in case anyone wants to take a look at how it's set up. I'd also be more than happy to copy/paste any relevant files into this thread, or provide the compiled app that's running on my watch.