Please add following code in your theme’s (child theme’s if any) functions.php
add_action( 'fep_autosuggestion_arguments', 'fep_cus_autosuggestion' );
add_action( 'fep_group_members_suggestion_arguments', 'fep_cus_autosuggestion' );
function fep_cus_autosuggestion( $args ){
unset( $args['search_columns'] );
return $args;
}
Let me know.