Hi @larsatevabaltser 

Welcome to the Sonos Community!

It’s very likely that either someone you share your home with or a visitor opened the S2 app while on your network and opted to upgrade your system. The best way to prevent this is to educate your housemates not to use the S2 app and certainly not to upgrade the system, and to enable a guest WiFi on your router for visitors to use - that will isolate them from your devices. You will need to change the password for your standard WiFi, however, and update it on all your WiFi-enabled devices.

Looking at your account, I see only a Play:1, however, and even if there’s a Play:3 somewhere, they both support S2 - the only reason to stay on S1 is if you possess speakers that will not accept S2. You may have another Sonos account with such speakers registered, of course - if so, please ignore this paragraph.

I recommend a reboot of your router - please switch it off for at least 30 seconds. Once WiFi is back on, please ensure your phone is connecting to the same access point (if you have multiple WiFi access points) and to the same band (2.4GHz or 5GHz) to maximise chances of success.

If this does not work, I recommend you get in touch with our technical support team, who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.

I hope this helps.