Not sure what’s happening here. You’ve set up the system on your phone and while you are at the location it shows on the owners’ phone, but when you leave it doesn’t show anymore?

No, I set up the system using the mobile app on-site, but when I am inside the rack room, the connection is successful and I can control the system. However, if I move to any other area, for example, other rooms, I lose the connection and the system disconnects from the mobile app. This happens even though the entire villa is covered by internet, and both the streamer and the device running the Sonos app are connected to the same network

Try disabling 5GHz wifi on your router. Chances are your phone is flipping frequencies when you move around, and your router does not handle this correctly.

If that works, fix the config of your router or get a better one.

Hi ​@Zaid_Daraghmeh 

Welcome to the Sonos Community!

Sorry to hear of this issue you are having with your room going missing from the app when you move around you home.

Although ​@controlav may be onto something there, I also think that this could happen if you have multiple WiFi Access Points - if this is the case, 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.

Unfortunately, I contacted the technical support team through live chat, but no one provided support to resolve the issue. Therefore, I need an expert in Sonos to join me remotely so we can solve the problem. I requested this from the technical support team via live chat, but no one provided me with any information about a person I could contact for such assistance.

Hi ​@Zaid_Daraghmeh 

Remote assistance is available, but only during a phone call - please call in rather than starting a chat.

I hope this helps.