Spotify Connect - Multiple Speakers/Devices

[user-removed]

I have had Spotify Premium for around a year now, I have two Sonos Play 5s and 2 Play 1s, they have worked almost seamlessly with Spotify all that time until now. The Spotify app can see the Sonos speakers listed but refuse to connect to them, this is both on my laptops and the Android app. I have uninstalled both apps, cleared all data and cache, removed the Spotify service from Sonos, rebooted the router, but nothing. The Sonos speakers work fine from the Sonos app. Can anyone offer any more help? 

[user-removed]

Interestingly after 2 days of trying everything just seems to have started working again. 

[user-removed]

So come to use Spotify again and play to my Sonos and the same thing has happened again, it just refuses to connect to any of my speakers. This is becoming far too much of a pain to the extent I'm looking at cancelling my Spotify subscription as it's becoming a waste of money if I can use it.