When a new WhatsApp Chat is received without an existing contact, a new contact record is created.
We want to merge the created contact with an existing record but after doing so, a new contact is still created when a new message is sent by the customer.
NB. Responses sent to the merged contact are received
Update: using the out of the box merge prevents any further messages from being received. We 'merge' by modifying the Contact in the Contact Identity and Chat tables