Hi Tony,
Had a thought for something to try...
I presume you're setting a fixed IP for the MC200 using MAC IP Binding?
(I don't have a BT HomeHub so typing blind here)
This fixed IP address should be OUTSIDE the DHCP range of the BT HH.
So have a look at the DHCP IP range in the settings of your BT HH, at a guess 192.168.1.67 to 192.168.1.250.
You need to set the static IP of the MC200 to a number not included in this range, so lets call it 192.168.1.50 for example, I think you have it as 192.168.1.68 at the moment which is inside the DHCP range.
Otherwise the DHCP in the BT HH might assign the static IP you have already used to another item on your network as well, and then you'll get IP conflicts.
Once you've changed it to .50 then you will need to turn off your MC200, reboot your BT HH, wait for it to fully reboot, and then turn on your MC200 again.
Cheers,
Rick