I’m not sure if you’ve already tried this with your statement “fixed max address” but can you read my article here: Tips & Tricks - Resolving random issues impacting Sonos devices.. | Sonos Community

What router do you have? What device is running the app?

@controlav : router is a mikrotik hap ac lite. App running on iOS 16.4 . Am wondering if this is not happening since last Sonos app update ?

@UKMedia : thanks . Have allocated a fix IO address for Sonos max address. My internet provider tels me that the Sonos appears connected and responding to the ping . Nonetheless the bar still doesn't appear in the app ("system" is in grey)

Check the app still has “local network” privileges.

Check your router’s Admin pages to see if the Arc is connected to your local network.

On your router’s Admin pages, compare the frequency your Arc is connecting to the frequency your phone is connecting to WiFi. If they are different, get a smarter router that can handle that.