Perhaps see if this thread assists to resolve your issue…

To quote from the linked page: “I found that by default, Aruba WiFi controllers (mine is a 225 running version 6.4.4.8-4.2.4.4_57496) drop broadcast & multicast traffic between attached wireless clients, which is used by the Sonos Controller app to find the Sonos.”

Since a network is made to let your devices talk to each other - that's why it's called a network - I am amazed by such a (standard) setting.