not receiving SMS messages on iphone X 16.2

If you have followed all the steps and instructions in Related Article: If you can't send or receive messages on your iPhone or iPad and if you still need help, get more help and assistant from Apple directly, see Contact Apple for support and service -> Contact Apple for support and service – Apple Support (UK) 

You need to be connected to a cellular voice network for SMS (text) messages, and both cellular voice AND cellular data for MMS (picture) messages. Are you?