Make sure that the Unifi switches are set for STP. Also, if you have a UNIFI PRO, note that it does not support STP. Don’t wire any SONOS units to the PRO. Yes, I know that there is a STP setting in the controller, but this sets the default for Unifi switches, not the PRO.

I am experiencing similar troubles with certain Sonos components dropping off since the recent ‘upgrade’  I no longer seem to be able to have  all components online at the same time.  I do not use unifi AP in this house, only a single StarLink router.  But, Sonos does report good wifi at each component location. In another multi-story house I have, I have 4 Ubiquiti AP and Sonos was solid, however that was before the ‘upgrade’. I am not at that house so I cannot report on that system. Good luck to us all

Thank you.  I will confirm all switches are set for STP.  I’ve unhooked all ethernet cables from the Sonos amps.  Don’t want to deal with that “network storm” again.  :-) 

In my Unifi setup, all SONOS devices are WIFI only.  That is four Play-5s, two Moves, two Subs (Gen 3), one Amp, and one TV Sound Bar (not sure on the model).  I installed the Unifi system in that house last November and once I switched over all the SONOS devices I had good performance all Winter. Before Unifi I was using a Mesh based system to distribute WIFI, with poor SONOS performance. As noted I am now away from that house, it is my Winter place. I hope once I get back in the Fall, I continue with the same performance. I am about to switch over my Summer house to Unifi in the next couple of weeks. I guess time will tell on SONOS, my ‘plan’ is also use full WIFI connections to SONOS products.