It’s quite likely that your router is getting muddled with its IP address assignment during the Sonos system multi-device reboot, post-update.

What may help in that situation is to reserve/make static the Sonos IP addresses in your routers DHCP reservation table. Consult your router user-manual to make those changes. The device IP addresses/MAC addresses are shown in the Sonos App ‘Settings/System/About My System’.

Hope that assists. 

I don’t have my PLAY:3s set up as surrounds, but there is no dropping whatsoever on them, and I’ve been listening to them for at least 4 hours straight. If I were to guess, there is some sort of new wifi interference in your environment, either from inside your network, or possibly outside your home. 

The surest way to confirm this is to submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

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 phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

The static IP setup solved my update / power fail issues.

The WiFi cleanup solved the rest of them. I got most of that done on my own but needed Sonos support’s assistance (via diagnostic) to sort out the last couple issues.