Could you perhaps have multiple spanning trees active?
Your HP switches are running Rapid Spanning-tree 802.1w as per the screenshots and I believe Sonos runs STP (802.1d), It is configurable on the HP switches... you could try it if possible...
Not sure what root port and root path cost affects the election of root bridge, but that might have something to do with it.
I advice you to adjust the path costs for the switches, since they are running RSTP. Either, run them in classic STP, or set the path cost for each port according to classic standard (RSTP have some advantages over classic that you may or may not care about). I have successfully managed to get a managed switch as the root bridge for a Sonos system, but the reporting from the STP page was inconclusive (https://en.community.sonos.com/troubleshooting-228999/only-tertriary-nodes-how-is-it-possible-30888). This was a long time ago though, and I don't remember exactly what I did.
But baseline, path cost needs to be correct for any port that has Sonos gear connected, and also for the link between the switches (any switches that has Sonos gear connected). If you do that correctly, turning on/off wifi has no relevance for the performance of your system. This is probably something that you should try to fix first.
Thanks for the replies. The reason I used RSTP was that I had read in the HP manual and in several other posts/forums that the RSTP would default down on ports with devices using STP-legacy, but as you point out the logs don't show that to be the case.
So, I've been able to test some of this remotely, but will have to finish when I'm home tonight in case it set of a broadcast storm and shuts down internet at home while wife is there alone!
I have set the 1920 'core' switch to STP mode and path cost using 802.1d, which did assign 'legacy' path costs to those ports. 🙂 On the remote 1810 switch, setting to STP/802.1d does not correctly set the path costs, they remain at 802.1w values, so I'll have to manually change the path costs. :?
On this post (https://sonos.custhelp.com/app/answers/detail/a_id/2129/~/sonos-stp-switch-settings) and others, I have seen that the cost for ports with sonos devices should be set to 10 (not 19, which is standard for 100Mbs) - do you have any input on this approach?
Also, on the port on my core 1920 switch that connects to the 1810, it's a 1Gb connection, so I would imagine that keeping it at 4 is correct?
ratty - I'm not sure how to test whether there are multiple trees. My understanding is that only should occur under MSTP and only if you set up regions - but I am hardly an expert.
10 or 19 shouldn't matter, the total cost just needs to be lower than what the wireless links would be set at. It varies depending on signal strength, but they are usually between 150-300.
And yes, setting the gigabit links to 4 seems like a good choice. Not that it matter much if you only have two switches and no redundant paths 🙂
Thanks - this seems to have fixed the issue, as the sonos stp is showing the MAC of core switch as root. Also, the Matrix lists the wired devices as secondary nodes and the wireless devices as tertiary nodes - none are root. Further, setting the port from core to secondary switch to 4 and the sonos ports to 10 (or 19) seems to have the sonos units all working as I would expect: the connect looks like it is getting signal from cable and the 3 wireless speakers on far side of home are getting wireless signal from connect. None of the wired ZPs are forwarding signal to Connect or the far speakers.
