New ST Hub + Sonos discovery

I bought an ST Hub last week, but I’m unable to get it to connect to my Sonos system.; a Playbar and two Play:1s.

The Playbar is connected via Ethernet to a switch (via another switch) into the same router that the hub is on. The Play:1s connect via SonosNet.

Tried physically connecting both devices to the same switch, still no discovery.

I did a broadcast ping across the network from a Raspberry Pi plugged into the same router - finds the Playbar no problems.

Really stumped. Emailed support who were unable to help.

Any suggestions?