I've got a full fledged Sonos setup, my comments:
If you are using ANY sort of auto-channel-switching on 2.4GHz, don't do it. Sonos's mesh networking can't deal with channel changes at all. Feel free to leave it on for 5GHz, but set up a static channel plan for 2.4GHz.
Or... If you can use a dedicated SonosNet (they call it BOOST or BRIDGE), I would recommend that if you have more than 1 Sonos speaker. This will let Sonos set up its own semi-proprietary 2.4GHz network which all the speakers mesh with. I find that this is more reliable especially if you have multiple speakers, as they do some magic sauce with realtime speaker synchronization and you don't deal with competing wifi traffic.
A dedicated SonosNet is set up by either wiring in one of your speakers, or wiring in a Sonos BOOST/BRIDGE device and then all your speakers can be wireless.