Plugin Settings are getting saved, but not retrieved

I followed this tutorial on settings: https://plugins.jetbrains.com/docs/intellij/settings-tutorial.html#the-appsettingsconfigurable-class

I copied the code examples verbatim. When I run the plugin, I see the settings, and I can save the settings. However, if I close the Preferences window, then bring it back up, the settings are not retrieved. I can verify the settings are being saved in the XML file behind the scenes. Is there anything missing from that tutorial, or has the API changed from that making the settings retrieval not work?