No it looks the link to the mix-cloud playlists is not working at the moment. It needs fixing, I suspect.

Are Sonos actually planning on fixing it ?....I've noticed as well, on Souncloud, that the number / volume of mixes in a playlist has been significantly reduced ?.

I don't want move away from Sonos, but am starting to feel I may have to now...

You could perhaps report the issue you’re seeing to Sonos Support. Here’s the link if you want to let them know (it’s a matter for you)…

 https://support.sonos.com/s/contact

I’ve reported a couple of issues myself.

I am also unable to access my playlists on Mixcloud. This is EXTREMELY frustrating Can anyone tell me, how do I actually put in a complaint to Sonos,

Same problem. 
 

if you don’t want to play from the Mixcloud app a work around (bad but you get your music) is to load everything up in the Mixcloud app in your listening queue.  
 

then go to Sonos app and view your Mixcloud queue.  That layer, the queue, is working. 

Yes, major issue. Unless fixed my commitment to Sonos goes.

Same here, new Sonos App absolutuily crap!! WTF Sonos

None of my mixcloud playlists are there, when I select who I follow nothing returns, Also when I add playlists via the desktop app, not working on the mobile app.

Man, why do you guys mess things up with new versions, the old app was fine, at least everything worked…

Everyone should log a case https://support.sonos.com/en-us/contact .  They will want you to submit a system diagnostic first.  

See 

I’ve send them an extensive video of what is not working with Mixcloud. No fix date yet.. They have to fix a lot of non functioning basic stuff first I guess.. grin :-)

Video: