Submission + - 2nd generation Google Chromecasts stop working globaly (tomsguide.com)
Google is already working on a fix, which only affects the 2nd generation, including Chromecast Audio. In the meantime, users are advised not to reset to factory's default. But if they did already, a user suggested a hack to set the mobile date to before March 9 2025. So the device is reconnected to your network via Google Home app (in hope to automatically receive the fix, when available)