Hey there,
I am really sorry for the delay of this reply as it is a weekend for us here.
I've checked on your site, it seems like this "Khmer" is one of your site Superadmin username, do you want to allow user to search username on Easysocial search engine?
If yes, you have to do following step from your backend :
1. Change to index username setting ->
http://take.ms/Tc6Sw
2. Go to smart search component and clear all the index then re-index again ->
http://take.ms/mYiHd