Thank you for reaching out to us on forums, our sincere apologies for your service interruptions. We rarely take system down for maintenance but since then system working resumed. For any other queries, please feel free to connect https://www.dynadot.com/community/about/contact.html
I saw a post asking for maintenance schedule (https://www.dynadot.com/community/forums/f0-customer-feedback/maintenance-schedule-1316.html) and a dynadot team account answered there will be maintenance schedules in the engineering corner but there are also no newer ones there.