How to get the display name to automatically appear on the To line when when I click Reply?

I have a person in my contacts (address book) where the Name value is "First Last" and the Display Name value is "First Last (email address)". If I start a new email and start typing either that person’s first name or their email address, Outlook will provide a dropdown menu with the desired display name as the first choice. So that’s cool. The result in the To line is “First Last (email address)”.

However, if that person initiates an email and I respond to it, their email address will appear in the To line, not the display name. I want the display name to appear, not the email address. How do I get the display name to AUTOMATICALLY (repeat: automatically)* appear in the To line when I click Reply?

*I already know how to NON-automatically get the display name to appear.

P.S. A tag was required. I don't know if I have Classic or New Outlook. I flipped a coin and chose Classic.