Assume that you log on to Outlook Web App (OWA) and create a contact in Exchange Server 2016 while the following conditions are true:
The first or last name of the new contact is pre-populated in the First name field or the Last name field, as appropriate.
The email alias of the new contact is the same as for an existing contact.
In this scenario, the First name field or Last name field of the other contact may also be pre-populated to have the first name or last name of the existing contact. In this case, the new contact may be merged into the existing contact in Exchange Server 2016.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.