That's quite interesting indeed. Could be someting.

I will post this on  https://community.spotify.com/t5/Other-Podcasts-Partners-etc/Spotify-Connect-has-stopped-working-on-my-Sonos-products-Port/td-p/6580057/page/2 as well and will contact Spotify about our experience, however reading the thread, they donot have a solution yet without loosing a lot of data/history of your spotify account (creating a new one and migrating some of the history data but not all).

Today at around 9:00 AM suddenly could play through Spotify connect with my Spotify account.

What i did earlier this morning, in Spotify, account, Security/Privacy, Apps: delete spotify. Previously, i did the same, but Spotify was still visible and connected in the Sonos App under connected services.

But now spotify has disappeared in the connected services and problem is solved and Spotify on my account can play through Spotify connect.

Hey Pierrrke, that´s great news! 

I couldn´t quite follow what you did. Seems you mention Spotify and spotify, nothing about Sonos. 
Would you mind doing a 1,2,3 step guide? Thanks in advance :)

Sorry for the confusion. Was a typo.

1. was earlier not able to remove the spotify connection in the Sonos App on iPhone as well as iPAD. Got an error when removing the spotify connection and the spotify connection wasn’t removed and stil visible in the Sonos App
2. Logged in to the Spotify website with a browser. Then go to account overview, Security/Privacy, Apps: delete SONOS access. Previously, the last couple of days, i did the same, but Spotify was still visible and connected in the Sonos App under connected services. Now Spotify has disapeared in the Sonos App under connected services

That did the job for me, or Sonos or Spotify did something also in the background.

Sufficient to repeat above steps?

Big thanks! I have also tried those steps before but will do it again since it worked for you. 

Otherwise i will factory reset the whole Sonos setup. Which is a pain tbh

Goodluck, hope it works for you as well. Mind that earlier i deleted the Sonos acces in my spotify account through a browser, but was still visiable in the Sonos app as being connected.

That changed this morning.

All the best and let us know how you solved the issus as well ;-)

Regards

Update!

I had no luck with the solution that worked for you.
I had to factory reset every speaker and re initiate the system as a whole. Pairing speakers for stereo, adding services, adding google assistant. But that did the trick! Now i works very well :)

I have noticed that a feature called Truplay is gone from Sonos Five and One. Weird, perhaps not supported on those anymore? On the Move there is active Truplay still.

That's a nightmare . Good for you that is working again.

So factory reset of all Sonos devices and buidling up from scratch in the Sonos App did the job for you.

Cumbersome no doubt.

PS I have Sonos One SL and Sub mini twice in two rooms. The Trueplay is under My System, select stereopair room, scroll down en under sound you should find Trueplay.

Thanks for the answer, nope the Trueplay feature is gone. :)

Well sound is good anyways!

Had the same problem. Removing and readding spotify as a service in the sonos-app seems to have solved it (so far soo good)

Lovely!

Same here. Working like a charm via Sonos app, but not via Spotify Connect. Once Spotify is closed so is the music. Did all the above things, negative. Think it is Spotify issue

It probably is! Did you try to reset your whole system? Do "forget system" and start over. 

Nope but the same issue is with a couple of my Amazon's Echo Dot 5. So I guess I'll just wait for the Spotify update

Sure but nothing has changed in my settings. Still think it's a Spotify problem.

The same here in Italy since yesterday.

some of my customers complain that the system stopped working. Usually I install ERA100 speakers in group of 4 reaching system with 24 speakers mounted on a bracket high on a restaurant/pub wall.

Please Sonos give us a procedure ASAP!