S2 controller app dropping rooms

I’d recommend a refresh of your local network. Unplug all your Sonos devices. Reboot your router. Give the router a couple of minutes to come back up, then plug back in your Sonos devices. Give them a couple of minutes to reboot and reconnect as well, then test. 

That is the general useless “did you try to turn it off and on again?”.
I’m a network engineer myself, and I see the same behaviour on my enterprise grade system too, since S2. OP also states he doesn’t have an issue with the Sonos speaker on a S1 controller, so very unlikely his network is the cause.
I did notice when you unplug/replug the speakers, they show up again for a brief moment… but that isn’t the solution we’re after.

That’s indeed the general ‘it might be a duplicate IP address issue due to problems with your router and improper IP assignments, which also fixes potential issues with DNS data not being transferred through the system properly‘, although the latter is not the issue that this user is experiencing. 

If you are indeed a network engineer, you’ll be familiar with both the more complex way that Sonos interacts with a network, as well as the challenges presented by some routers not handling proper DHCP assignments due to failures of various types within the router, exposed by the Sonos doing a soft reboot during the update process, and requesting new IP addresses. 

But I’m not a network engineer. I’m just familiar with the way Sonos works, and have been helping folks long enough to know that in greater than 95% of the cases, this resolves the issue. I’m also smart enough to know that it isn’t a silver bullet, but once it has been completed unsuccessfully, can then focus on other, rarer potential issues. 

But since you’re a network engineer, and must have greater knowledge than I, I will bow out, and let you resolve this user’s, and your, issues. 

I don’t know which part of: “The Play:5 still on the S1 controller operates normal and doesn’t drop off” you missed. Also personally never had routers hand out duplicate IP addresses. I’ve seen many ISP endpoints stop handing out IP addresses, bc the DHCP pool was too small, and/or leases of devices that left the network didn’t expire already (to make the IP address(es) available again for new clients).
I do agree that making IP reservations based on devices MAC-addresses outside of the DHCP scope, rules out many issues people have with bonjour/mdns and caching in their computers/other endpoints. That way, you simply cannot hand out the same IP address twice. Most of the time duplicate IP addresses are the user’s fault, bc they manually assigned one on a device, and didn’t exclude it from the DHCP scope. And maybe when the timing is right (and such IP is handed out by DHCP), and afterwards they start up the manually assigned device, mayhem happens… but any other order, prevents the router from handing out that IP, as it should be in it’s ARP cache.

I have the same exact problem since I upgraded to S2 and multiple attempts to get feedback from Sonos have not been answered.  Please note that the Sonos App on the MacOS is not dropping the speakers.   It is only the S2 app on my iPhone 11 (iOS 13.5.1).  And I did try to reboot the router.

I noticed too, that while the devices drop from the iOS controller, their Airplay keeps advertising.

i also use Roon, and while they dropped, I can also still see the Airplay endpoints, but the sonos ones disappeared. Not all Airplay endpoints are able to stream though.

Unplugging 1 speaker from mains, or ‘reset/reboot’, usually brings back the entire system.

I’m considering resetting all speakers, and do a downgrade to S1.

Upgraded to S2 - worked good for a week - now everything is dropping and can’t find my speakers????? What is going on?   Had Sonos for 8 years - now all kinda of problems!   This is not good - maybe sell everything and switch to Bose !

I have rebooted modem and router - nothing seems to be helping - music stops and speakers drop off.  I have my sonos using a  separate channel on my wireless router - is this an issue with S2?  Is my router no longer compatible? Is there a list of S2 compatible routers somewhere?

I fixed my problems.  First, checked my matrix: https://forums.homeseer.com/forum/media-plug-ins/media-discussion/sonoscontroller-dcorsus/1283672-sonos-network-matrix

Saw I had major wi-fi interference.  Purchased a Boost and switched back to SonosNet.  So 8 speakers on SonosNet and my Move on wi-fi - every thing back in order and working great.  You can group SonosNet speakers and wi-fi speakers with no issues. 

 i have the same issue - before upgrading to S1 ourer sonos was stable as a mofo,

We have a unifi network - all speakers worked like a charm

We have 2 x S1 + 1 Move + 2 x play5 - after upgrading its becoming very useless and really really unstable.