That’s odd, I’m not having any issues on my iPad, using the current iOS controller. Which suggests a local issue. But I’m not sure if it is a network issue between your controller and the speaker(s), or the speakers themselves not being able to reach the data from outside your network. I don’t use much ‘outside’ stuff, but everything is appearing. Let me know if you want a screenshot. Of course, mine is in English (yea, I had to tease you there), but I wouldn’t think that could be the issue…but then again, I wonder. 

Sometimes hard to tell, but ‘updates’ to various port blocking styles of apps might change that process. You know the usual suspects. But I’d also likely recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Going back to the English thing, just as a test, have you tried setting the ‘native’ language on your iOS devices to English, temporarily? If you can, without breaking too much? That might (and I stress that) tell us if there’s an issue with the translation function. 

I'd suspect the phone and pad have done something odd while away from the home network, the usual "beat the suspects until they confess" (OK just power cycle them) would be my first step.

So many possibilities for them to decide not to cooperate, VPN, dns, cell data link, cached information from past connections it would be hard to pick a starting point.

I like the concept of ‘beat the suspects’ Certainly couldn’t hurt. 

Thank you. Not a very common occurrence then. I will see if it has changed when I am back from my next holiday in a couple of days.

Perhaps fewer holidays are indicated? ;)

Looks like the app is not authenticating to the Sonos cloud, which is where it gets Recently Used and the Services list. I would try re-logging in as owner in the app.

I see there is a new a app version too. I’ll try next week.

After restarting players, router and Deco Mesh and resetting the apps, I noticed the PC app still shows everything, while web app and iOS apps show nothing (see starting post).

I called Sonos and sent in some diagnostics from my iPad and the PC. Help was very patient. Nothing unusual showed. Restarted the Deco’s again and to my (and the Sonos’ representative’s) surprise the history and services showed again. Sent in another diagnostic, which Sonos would take a look at.

Only now I see that after choosing for example Spotify as a service the library will not load (“something went wrong”), so it seems we are only halfway there. I have no further time to resolve this today. See what the next few weeks bring.