Base Station Chirps at Midnight

My Ring base chirps every night at midnight (actually exactly 12:01) for a few minutes. I have disabled chirps for all modes in the app. In consultation with Ring support I have also reset, rebooted and updated the firmware of the base. What is the cause of this chirping and how can we make it stop. This is a new behavior that started about 1 month ago though the system was installed over 2 years ago.