Controller Offline

I own a Rachio 3. Recently switched from Comcast to CenturyLink and now my app tells me my controller is offline, continually. I troubleshoot the system and get it rebooted, only to have it offline again the next day. Just this weekend I moved the controller 50 feet closer to the modem, and now they are approximately 30 feet apart, separated by a door and about 6 steps to the basement. Still goes offline.