Within the Alexa app select the zone/room in question.  Within the next menu there is a preferred speaker that must be identified.  Often times the app will recognize the room,  but you still need to assign a speaker.  Once the speaker is selected and saved within the Alexa app for that particular room, it will play just fine.

enjoy!

None of these suggestions worked. She still says “sorry on Sonos is offline” and I have my Sonos speakers set as default. 

@steviez 

Do you currently have Alexa setup in multiple locations under the same Amazon account?

Yes.  I have multiple Alex devices throughout, in each room, as well as multiple Sonos speakers. 

Sorry for the confusion. When I mentioned multiple locations, I’ve meant if you also use Alexa from another site?

No.  Just one apartment.

In that case, try these steps below:

• Disable the Sonos Skill within the Alexa app. Do not re-enable the skill just yet.
• Next, open the Sonos app to remove Alexa voice services as well.
• Log out of all Amazon Apps on the mobile device, i.e. Amazon Shopping App, Alexa App, Amazon.com and Amazon Music.
• Go through the Alexa Setup in Sonos again.
• Follow the prompts to set up voice services which will require you log in your Amazon account, to link them together.
• If that's all worked you should hear the Sonos One say "Hello". Try asking it to play something like a radio station (Radio by TuneIn is enabled by default) and see if that works.
• If this does not work, or you are getting stuck at any stage, please post a diagnostic confirmation number and describe how/where it went wrong. 

Keep me posted whether or not this helps.

THANK YOU!!! I tried other suggestions, but only this worked. Have had this issue for a while. Closing and exiting everything as you noted, was the only thing that worked. Now my MOVE is working like a charm. Thank you very very much!!!

No problem at all! 

I tried everything you said, joined Alexa with my sonos and it said hello and speaks to me but when I ask it to play my music it says “playing songs in your library, sorry this device is offline”. what do I do?

You follow the advice here

https://en.community.sonos.com/amazon-alexa-and-sonos-229102/sorry-that-device-is-offline-6821288

 NOTE actions must be taken on PC or Mac browser

Tried it and didn’t work, and I’ve tried so many other things aswell

@archiekilp, do you have Alexa and/or Sonos setup at multiple locations or addresses? Alexa can have trouble with multiple locations on the same account.

Same problem, but I didn’t want it to use the Sonos speaker. It would try to play from so is, say it couldn’t connect & not play anything at all out of the Alexa speaker I asked to ply music. My fix was to remove any Sonos speakers as the ‘preferred’ speaker in all device groups in the Alexa app

I get exactly the same here tried all steps but doesn’t work and to be honest the Alexa integration on all my Sonos products is dire including the beam very unimpressed with the Alexa side of things 

@Treble I am sorry to hear about your issue. Can you tell me if you have Alexa and/or Sonos setup at multiple addresses under the same account?

I’m having the same issue…

I am having trouble getting Alexa to work properly... I have gone through the forums here and have tried disconnecting and connecting Sonos and Alexa many times but Alexa just refuses to work. Alexa is enabled on my Sonos but it doesn't do anything... when I ask what time it is, the time is wrong (1hr later than my time) and when I ask to play music by saying "Alexa play music", it just says "sorry that device is offline". What I really want is SiriusXM but when I ask Alexa to play SiriusXM it just says the app is not enabled (even though it is and is working fine on my other Amazon branded devices)... please help! I submitted diagnostics via the app with confirmation number 680562498.

Hi @tangfj, thank you for reaching out to the Sonos Community. I appreciate your detailed post describing the issue as well as the steps that you did. Let me help you with this.

I'd like to ask some questions to isolate the issue so we can create a path towards resolution.

Do you use your Amazon account in another home or location?
When you ask Alexa about time and the weather, did she respond correctly?

Let me suggest the following steps to see if this would work for you. I know that you have performed the troubleshooting below, it would be best to follow it step by step.

1. Open the Alexa app on your iOS or Android device.
2. Open the menu in the top left and tap on Skills & Games > Your Skills > Sonos > Disable Skill.
3. Deregister your Sonos speaker from Alexa by following the instructions on Amazon's website: Deregistering a device.
4. Disable Voice Control in the Sonos app. From the Settings tab, tap Services and select Amazon Alexa under Voice. Select the voice-enabled speaker from the list of Sonos Products, and tap Remove Alexa.
5. Log out of all Amazon Apps on the mobile device, including the Amazon app, Alexa app and Amazon.com in your mobile browser.
   • To sign out of the Amazon mobile app:
     • On Android devices, open the app and tap Menu > Your Account > Sign Out.
     • On iOS devices, open the app and tap the menu icon in the top-left corner, and then choose Settings > "Not gname]?"
6. Using the Sonos app, complete Alexa setup again. Follow the steps to log into the appropriate Amazon account when prompted to do so.
7. Once completed, try giving Alexa another command.

If you're still having the same issue after checking the steps above, I recommend contacting our Sonos Customer Care support to remotely connecting to your device to further assist you with this and to provide the best option for you.

Please feel free to reach out in the future if you have any other questions.

You're always welcome here.

This process fixed my issue; thanks for sharing