How do you stop search box from showing up in a message when you type "@"?

Outlook 2019 (NOT Outlook 365 / NOT Outlook.com / NOT Outlook app / NOT Outlook Web App)

How do you stop search box from showing up in a message when you type "@" in the message body?

The moment I type it, a box covers what I am typing and tries to search my contacts.

Options > Search has no effect on this feature.  I unchecked all the boxes, removed Outlook from the Index, and restarted Outlook but it won't stop this annoyance.

Thank you in advance!