Trouble connecting cellular network

I have had no problem connecting with our application and sql server using this connection string:

Server='url'
Database='DatabaseName';
User Id = 'UserID';
Password = 'Password';
Connection Timeout=10;

It has been connecting both through ethernet, wifi and cellular networks in various countries, but now we are on the faroe islands and all of a sudden it is not working through cellular networks, but is with wifi.