Someone just created an account with an emogi in their name

Go into SQL, right-click the Arena Database and select properties. On the General tab, there's a property for "Collation". You should see something like General_CI_AS. That "CI_AS" part determines if it is Case Insensitive (CI) in the search. It also has Accent Sensitive (AS). If that AS were changed to an AI (Accent Insensitive), then the search would match café when you have a WHERE name = 'cafe' query, as well as your coworker's name.

Maybe check with Arena Dev/Support and see if it is supported to update the Collation setting on the database, or maybe just the Name fields in the core_person table.

Interesting. I did some more reading, and it sounds like something best done when setting up the server. Fortunately, I am planning to migrate to a new one soon.

You can also cast the collation on the query itself and not have to touch the database, just don't know how that would affect performance.