Matthias,
The original APN I used for over three years was “three.co.uk” I was also advised to try “3internet” and also one other that I can’t remember. I have left it with my notes on the boat. None of them fixed the problem
The “three” pre-paid sim only had two months remaining of its 24 month validity.
So, now that I have established communication with VRM via a new EE sim, the old one is resting at the bottom of the canal !!
Regards, Mike