[Q] Unlocking tethering topic

I live in Europe, and my 95 year old mother purchased a Motorola Droid Razr which she was basically unable to use. She sent it to me. The phone is originally from Verizon, although the 4G LTE phones apparently come unlocked from them. I have rooted the phone, but am on stock Jellybean. When I put my Vodafone sim into the phone, the phone says 'unknown sim', I press ok, and the phone works fine. However, when I attempt to use the hotspot function, the phone says 'Your phone cannot currently connect to the Verizon server'. I contacted Verizon but was advised that there was no further unlock that they could do, with the IMEI etc. as, as far as they were concerned, the phone was unlocked. They advised that the 'lock' on the tethering actually came from Motorola (??), as these phones were shipped to them unlocked from the factory.
I would like to be able to use the hotspot function on the phone. There is a 'Configure Mobile Hotspot' link on the phone that is greyed out, and underneath it states 'Verizon Droid Razr 9981 WPA2 PSK Mobile Hotspot'. Does anyone have any information as to how this can be remedied - is there some setting in the phone that redirects the phone from Verizon, or where I can change the settings? I am not a developer, nor terribly familiar with the phone (yet)....Thanks for any assistance you can give.