Security issue in Tourism environment using separate wifi networks

Hello,

I am having an issue securing my Sonos speakers in a commercial tourism environment.  I currently have 2 Sonos One speakers and am looking to add about 7 - 10 more speakers to the system.

I have them on their own separate password protected wifi but guests with the Sonos app are still able to find the speakers and screw around with things like volume controls and pairing settings.  We see hundreds of guests a day and have a wine lounge and bar so some guests get antsy with the music after a drink or two.

 Here is my set up:

Running a Ubiquiti Unifi Network with 4 separate wifi networks:

3 are secured networks

1 is a public guest access channel used for guest access (required for marketing, etc). 

Networks are:

Guest (open to internet for guest access, metered, email authenticated)

Music (for Sonos exclusively, secured, not discoverable)

Staff (for staff, connection to server, firewall protected server)

Payment terminal gateway (for credit card machines, etc, third party firewall protected from bank)

Running 14 UniFi wifi access points for all winery wifi networks.

For guest wifi access we are running a guest log in portal through Ubiquiti.  Guests have limited internet access, no server access, cannot see or discover anything on the network.

2 - Sonos One SL

Last summer we had guests constantly able to get access to the speakers from their own sonos app and change the volume or song.

I have spent all winter working on different configurations to secure the speakers and then assign someone on our staff to attempt to “hack” it.  Initially the speakers do not appear, but when someone on the guest wifi opens their own sonos app, they are able to discover them with some searching. They are always able to get to the speaker and able to change the volume or song.  Note: they are NOT logging in to the Music network to do this.  They are seeing the speakers from the guest wifi)

I have reviewed my network security about a hundred times, what am I missing, I need a fresh opinion…  I need to make the speakers completely undiscoverable.

Thanks,

Jeff