Thanks heaps for your advice, I really appreciate all the help you are giving.
Have deleted all the profiles, created a new one and entered the settings advised as per screenshots but have now got a message "Invalid PVC" when trying to save the new profile.
Have also attached a screenshot of my Voyager modem's settings - I see that the IPv4 setting is static with DNS server numbers which I believe is required but the Vodafone modem will not let me select the static setting for IPv4, only the PPPoE is permitted. I have no idea how to change this.
Voyager modem setting below: