Mac Mail M1 showing main email address doubled when I click the drop-down menu for my contact next to recipient field "To:"

I noticed this strange duplication of my email address in the drop-down menu several weeks ago. Thus far I do not believe it has caused errors within the functionality of my mailbox, but it is absolutely causing errors within the functionality of my brain because I don't understand why it has happened and I'm afraid it will cause future issues...

As you can see in my screenshot, my primarily used email has all of a sudden duplicated itself. I realize I have several email addresses that I work with within my Mail application on my M1 MacBook Pro. I just don't understand why in the world it would've suddenly duplicated "la********@gmail.com" visually in this menu. It's bothering the crap out of me, as I check this drop down often to see what email address a sender has used to contact me - helps me know where they found me.

Any ideas as to how to get this to knock it off?

[Edited by Moderator]