I have exactly the same problem. I have tried the fixes and Alexa has stopped working, completely. My system is up to date.. can anyone help?
OK. So you tried everything suggested. There are two more things you can try. Please read carefully before doing anything.
Option I
1. Unplug all your Sonos equipment.
2. Unplug all devices that use Wi-Fi
3. Delete the Sonos and Alexa Apps from you phone and/or tablet
4. Unplug you Router_wait 30 seconds
5. Restart your router
6. Re-enstall the Alexa App
7. Plug in all Non-Sonos Wi-Fi products
8. Plug in all Sonos products except the Sonos One
9.Re-install the Sonos App
10. Setup your Sonos speakers...except the Sonos One
11. Setup the Sonos One (make sure Voice Services is enabled in the Sonos App)
12. In the Alexa App Go to Skill > Type Sonos in the search Field > Search > Tap the Sonos Skill verify that it is enabled.
13. Ask Alexa via the Sonos One to play music from Amazon Music
Or
Option II
Verify that the LED below the microphone icon on top of the Sonos One is on :8
Cheers
Together Everyone Achieves More = T.E.A.M.