Hey there,

It seems like we hardcoded that language, try download my attached file and replace into -> JoomlaFolder\components\com_easysocial\themes\wireframe\users\default.list.php

After you applied this file in your site, you can update these 3 new language string into your language file e.g JoomlaFolder\language\en-GB\en-GB.com_easysocial.ini

COM_EASYSOCIAL_USERS_SORT_RECENTLY_REGISTERED="Recently Registered"

COM_EASYSOCIAL_USERS_SORT_RECENTLY_LOGGED_IN="Recently Logged In"

COM_EASYSOCIAL_USERS_SORT_NAME="Name"