The next time it occurs run a diagnostic within 10 minutes. Record the reference ID but do not post it. Call Sonos tech support as they will be able to analyze the data an let you know:

• If it’s a network issue
• Failing network card
• Interference

You might also check your device for OS updates a well as your router. Also make sure that all Wi-Fi bands are active (2.4Ghz and 5Ghz).

I wonder if it’s the Battery Saver? When Battery Saver is turned on, the Move 2 goes into a deep sleep after 30 mins of inactivity, making it inaccessible from the app until you press the power button. In Settings - System - Move 2 - Battery Saver, you could try turning it off.

Also, if possible, keep the speaker docked or plugged in when not in use. This keeps it in a ready state rather than sleep mode.

(One other thing to try if these aren’t helping is assigning the Move a static (/fixed) IP address in the router. It’s possible that the Move loses connection whenever the router assigns it an IP address. I don’t know why the Move would be affected and not your other speakers though, but it’s the only additional solution I can think of.)

I have the same problem I love the sound but feel like changing to a different brand as just want it to work. Oura is sat on its charging stand but stills has issues Sonos please rectify. 

Have you followed any steps above?

I'm not sure how to run a diagnosis and going to try a static IP. Just want it to work like our beam does 

Mine goes a step further and disappears from my system and now won't repair 

Click this link to read how to submit a system diagnostic.