I went to rename a Sonos One yesterday as it was moving physical rooms. Alexa could not discover it, much to my dismay after having a perfectly working system for the last several months.
At this point, I can easily set up any Sonos speaker, enable Alexa on it and use Alexa through my beams or ones just fine. HOWEVER, while all Alexa-enabled speakers show up as ALEXA DEVICES in the Alexa app (and on alexa.amazon.com) NONE of them will show up as SMART HOME DEVICES.
This means that while I can use Alexa through Sonos to control things, I can no longer, for example, turn off my TV using Alexa through the Beam to control the TV connected on the HDMI ARC port.
I've tried enough combinations of remedies from other posts without success that I resorted to my best attempt at a clean slate: a factory reset of the only Sonos device I plugged in after logging out and uninstalling both iOS apps, leading me t to set up new system from scratch. This was after removing *all* Alexa skills and devices (not just the Sonos ones). Symptoms persist. Error messages are non-existent or useless.
I notice an uptick since yesterday of similar posts:
* https://en.community.sonos.com/amazon-alexa-and-sonos-229102/alexa-can-t-discover-3-devices-6819618 - Not answered at this time
* https://en.community.sonos.com/amazon-alexa-and-sonos-229102/sonos-beam-and-alexa-not-playing-nice-6819582 - Answered but not fixed, and yes I've tried the steps listed.
* https://en.community.sonos.com/amazon-alexa-and-sonos-229102/alexa-not-discovering-speakers-6819608 - Not answered at this time
* https://en.community.sonos.com/amazon-alexa-and-sonos-229102/can-t-control-lg-tv-anymore-6819604/index1.html#post16305913 - may or may not actually be the same problem, but certainly sounds like a general pattern of Alexa losing the ability to interface with Sonos devices as Smart Home Devices.
* https://en.community.sonos.com/amazon-alexa-and-sonos-229102/alexa-app-not-discovering-any-sonos-speakers-6791553 - a year old post with a solution (sadly didn't work for me) posted 6 hours ago.
I think it's also worth noting that the off-the-shelf solutions presented in the largest sticky thread on this (https://en.community.sonos.com/amazon-alexa-and-sonos-229102/resolving-the-majority-of-issues-with-alexa-on-sonos-6798039) have been tried, and sadly do not help. In fact I notice there's a post on that thread (by jwelch649 an hour ago) complaining of an issue that sounds much like my own.