Sorry - should have typed “4G data reception” above!
Your coverage checker shows no 4G coverage for the postcode SA33 5EX. However, if I tick “I have a 4G Voice Calling compatible phone”, this changes to “Excellent 4G coverage”, saying I should be able to use the internet. How can this be? My understanging of 4G Voice Calling, (voLTE) is that is uses the 4G signal to carry voice, so if there is no 4G coverage to start with, how could the phone make a difference?