My wifi guest channel stopped working this week, I rang 150 and got for help. I think recent changes by myself to the hub3 settings page may have stopped it working but having done a pin reset I still could not connect my now box to the guest channel. I also I had trouble with the settings page password.
I have disabled the guest channel and and connected to to the normal 2.4g channel and the now box works.
The trouble may have been caused by adding mac filtering for connected devices and I am now using and wpa2 security and may have done other setting changes that caused the problem.
Connected devices do not show if on the guest channel. A separate network for iot devices sound sensible, rather than using a guest channel but would nean using extra routers and equipment.
The guest channel may be less secure and can be a target for hackers who can use it to help to compromise the hub by dos attack etc to hack the hub.