Lost connection after changing my Network Switch

What type of network switch is it - Unmanaged, or managed?

If it’s the latter, then maybe see the link below for the recommended STP settings for such switches in a wired setup… 

https://support.sonos.com/en-us/article/configure-stp-settings-to-work-with-sonos

Unmanaged switch. 

I assume you’ve perhaps already tried different Ethernet cables (& Ethernet ports), between ‘Router & Switch’ and ‘Switch & initial Sonos product’, but have you tried wiring a different first ‘Sonos device’ as the root bridge, just to see if that may resolve your issue. Maybe it wasn’t your original switch where the fault was in the first place? .. (Just as a bit of a thought🤔?)

Have tried plugging into both switches. Multiple ports. Multiple cables. 
 

Tried starting with each of the 4 devices. Same thing every time. 
 

If I try and connect wirelessly, it actually finds the device. But then won’t connect to the network and asks me to try via Ethernet. And it starts again. 

It’s driving me bananas. I literally see the device on my router. Only thing I can think of…is for some reason my phone is connecting to a different wifi channel or something. Pretty sure I have the 5ghz wireless off. But maybe will check that next. Ie is 2.4 vs 5ghz causing an issue??

Are you using the S1, or S2 (New Sonos), App? Presumably nothing has been changed on your router since you had this issue or have you reset your router?

Are you using a mobile only controller device that meets the current system requirements, as shown here:

https://support.sonos.com/en-us/article/sonos-app-requirements

Network for a WiFi connection needs to be 802.11b/g/n compatible and I recommend using security mode WPA2 personal - shouldn’t matter though for a wired link.

It sounds like it might possibly be a mobile Sonos controller device issue - do you have another (compatible) mobile, or tablet, that you can try, just to see if that may perhaps work for you?

iPhone 16. Old Sonos 1 app since that it all that works with the Connect line I have. Everything was working perfectly until I had to change the switch. 
 

Maybe I will try turning off the switches and just attaching the Sonos directly to the router out of curiosity. 

…and finally, that worked. Had to remove my network switches from the equation and hook the Sonos up directly to the router without any switches connected to the router. Then add each product. Worked. 
 

Then disconnect the Sonos from the router, connected it to a Switch. Then reconnected the Switch. Still works. 
 

Weird. Guess the Sonos products do not like to be setup when first connected via a network switch and not directly to the router?

What specific make/model of switch is it?

Hardware is as follows:

Modem:   Xfinity xb6 in bridge mode (Rogers ISP into this)

Router:    Asus RT-AX86U, one port out to the YuanLey uplink port 

Switch 1: YuanLey unmanaged 28 Port Gigabit PoE with 2 uplink ports, one of the ports out to the BV-Tech uplink port

Switch 2: BV-Tech unmanaged Switch with 2 uplink ports

Still having other issues with getting both switches to play nice for some reason.  Lots of loopbacks depending on how I connect them.  Basically right now the only way I can get them to work is to use a crossover cable from an unused port on the YuanLey to the uplink port on the BV-Tech.  Which is really odd, wouldn’t think I’d need to use a crossover cable in this day and age.

Yes, a real strange one, especially with an unmanaged switch. I’ve not personally heard, or seen, the issue mentioned before. Anyhow, I guess all’s well that ends well for the start of a new year.

I’m curious, what is the specific make / model of the switch? There are some unmanaged / ‘smart’ switches that have been know to caused issues with STP. 

Links to the switches are in the main post.  From Amazon as well below if easier:

YuanLey: https://www.amazon.ca/dp/B09MRKJWW2?ref=ppx_yo2ov_dt_b_fed_asin_title

BV-Tech: https://www.amazon.ca/gp/product/B01MQHD54L/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Sorry, didn’t see the original links. I’m not familiar with those switches, but the spec on Amazon says first one has a VLAN port isolation mode, where all ports see the uplink (Internet/router) but are isolated from each other, that would definitively impact Sonos network requirements if enabled.