MIB2.5 CANBUS Gateway for retro-fitted Columbus / Discovery Pro

Folks,

Very unusual and specific issue I've got - and I'm not too worried if it isn't fixed (because Android Auto is sooo much better). 

I have retrofitted (and got correctly coded by pab567) - a native MIB2.5 Columbus to replace my MIB2.5 Amunsden.  The car reports no errors on CANBUS, but try as I might, I cannot get the Columbus unit to connect to Skoda Connect.  You get as far as the Columbus unit saying it is checking the backend services - and no further.

I suspect one of two things is happening here;

1) My CANBUS gateway is snookered.  I know there were issues with the gateway modules that dealers were fixing.  Are there different gateway modules for the Amunsden and Columbus?  If so, what is the correct part number for the Columbus gateway module?

2) VAG's backends are unhappy that my car's VIN has a Amunsden against it - instead of a Columbus that is presented and the back end is borking.

Communication to the MIB2.5 unit from my phone is via a Wireless Hotspot.

Your thoughts as always on the Reply button.