Still playing around to try and understand the underlying issues with Sky Hub and UPnP
With the Sky Hub in wireless mode and a Netgear device in access point mode (connected via lan cable), the Unitistar is very happy when an ethernet cable connects it the the lan port of the Netgear device.
If you connect the star directly to the Sky Hub via a lan cable, connection becomes unreliable.
Why would that be? The same cable feed goes from Sky to the Star regardless of the Netgear being in the loop - WiFi is always via Netgear Orbi so why would the system be sensitive to connection to the Hub versus the Orbi?