Searching AD/Exchange GAL from iOS: 4 Character Minimum?

Valued Contributor II

I have found that when I am on a mobile device using Active Sync (iOS 9-based iPhones etc), and searching for a fellow employee in the GAL, I have to enter at least 4 characters for the search to work.

Our employee user names are only 3 characters long, and we have lots of employess who have first names and/or last names shorter that 3 chracters also.

Does anyone know if this character search limitation is specific to iOS, to ActiveSync or if it can be modified server-side in AD/Exchange?