- apply the new switch (v 4.0.55 or higher) and controller versions to your Unifi Gear,
- move the switches back to using RSTP and
- Modify the port settings on the LAN ports that connect to Sonos Gear, - turn off STP.. (Turn off Enable Spanning Tree Protocol)
I've been running this setup in our home for a few weeks now and finally all my LAN gear can get DHCP in under 5 seconds (earlier it was o
ver 45 seconds with STP)
hope it helps