This is why your alexa is offline and how to fix it
Echo (4th Gen) Offline under Connected Devices - Ring App - Ring Community
Is something wrong with this setup? Trying to get Alexa to play on preferred speaker but I keep getting error saying “device is offline”, however I can play directly to the speaker
Why does Nest Camera Keep Going Offline? | Smart Home Devices
How to Fix It When the Alexa App Says the Echo Is Offline