What are the three things you’ve tried?

My first option would be to wire a speaker directly to the router, and give the all five minutes to recognize the change, or just power cycle them. That depends, of course, on which Sonos speakers you have. Not all of them have Ethernet ports.

Then I’d make sure my router conforms to the Sonos Network Requirements FAQ.

Finally, if the devices still weren’t connecting, I’d call Sonos Support directly to discuss it.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

I read through the community response and tried the following:  

1. Ensure to disable QoS feature.   
2. Ensure that Airtime Fairness defaults to OFF. 
3. Turn off "Enable Block All Devices"

I have not hardwire a Sonos One Speaker to the Router or the two different sound bars to the wifi router.   I need to find the instructions to do so.  

Also, one additional thought, I have a Sonos Boost device connected to a hub that ultimately connects to the router.  Would this have any impact? I am not sure it would, but thought I should ask.  

You need instructions on how to wire an Ethernet cable to a Sonos speaker (not a surround speaker or Sub) to your router?

That oddity aside, the existence of a BOOST does change the network somewhat. It wasn’t mentioned in your original post. You use the term ‘ultimately’ when describing it. It should be wired directly to this new router, with nothing in between the two. All speakers except Roams or Moves should then connect via SonosNet. If they’re not, do a simple power cycle. 
 

If you’re still struggling, call Sonos Support directly.

I understand how to plug in an ethernet cable.  I assumed there are instructions to follow to make it work beyond plugging the sonos one via ethernet to the router.  Sounds like just plug the sonos one into the router and go into the app to set it up, no specific instructions.  

As far as the boost, you are correct, I forgot that I had it.  If it is plugged into a hub, your advising that will impact the set up versus if it was directly into the wireless router?

Absolutely. 

Power off the Boost. Assuming it’s wired to your internet gateway and the XT8 mesh hasn’t been put into bridge/AP mode your Sonos will be on the wrong subnet.

I have a largish Sonos system on XD6 (2-pack) and it’s been absolutely fine.

I have three XT8 nodes and my Sonos system connectivity is great. You have already commented on a few key config changes that should be made for the Asus system.

Have you spotted the Sonos article on WiFi setup? It’s here. You will note that Sonos is moving away from SonosNet and I don’t use it (ie I don’t have a speaker or Boost directly connected to my Asus router). Unfortunately the article doesn’t contain specific instructions for Asus.

Where I diverge from the article’s advice is that I have disabled Smart Connect in the XT8 config. This means I have separate 2.4GHz and 5GHz bands, and all my Sonos speakers are connected to 2.4GHz as I have the older Playbar and Play:1 speakers. My phone also connects on 2.4GHz which I find means a faster connection to Sonos.

After splitting the bands I’ve done the opposite: force all Sonos devices onto 5GHz except for the Home Theatre master players, which can only connect to 2.4GHz.

Also, all Sonos units except for portables are bound to specific AP nodes.

Yes, agreed. I bind to specific nodes and also use static IPs. 

Just to clarify, rarity’s comments. When you say plug the boost directly into you your internet gateway, you are referencing the Verizon Fios Modem that brings the internet sign into my house?