search box shows all results on a specific text when it shouldn't

I am getting row data from my viewmodel. Whenever i type "administrator", it gets all the result instead of displaying only text with administrator.

eg.
name
admin1
user1
user2

so if i type "admin" it gets all the results instead of just retrieving 'admin1'. Other than that it works fine. Does anyone kno why this is happening? any help would be appreciated.

Here's my code
//datatable
$('#administrators_gridView').dataTable({
"iDisplayLength": 25
});
//table element
<table id="administrators_gridView" class="">