Newbie to Zigbee problems connecting Moes Smart Knob to Sonoff ZBBridge

I have done quite a bit of HA using WiFi devices but this is the first foray into Zigbee as for Christmas someone gave me a Moes Smart Knob.

As I have quite a bit of Sonoff stuff I bought the Sonoff ZBBridge (I spent a while trying to check that it is also a hub an believe it is). Ewelink connects to the ZBB and I have got it searching for Subdevices. I have put the Moes in pairing mode and the green light flashes for about 14 secs, stays on for a bit and then goes off but it’s not connected.

Has anone else got this combination working OK?
Am I even using the right kit? I read on this group that connecting Zigbee via a WiFi bridge may not be a good idea. Can people suggest alternatives – I dont really want to spend a lot of money as I dont necessarily wish to commit to Zigbee.
Any other suggestions most welcome. Thanks for reading.

PS If this is in the wrong place I do apologise and hope an admin will redirect!!