Filter GridView through TextBox without loosing the checkBox inside the grid in c#

i have this problem about DataGridView with checkbox inside. i populate the gridview by using a data table and pass it to the binding source.

the problem starts here when i search on the textbox, all the checkbox become unchecked.

here is my code in filtering the grid using textbox

BindingSource bs;
bs.Filter = string.Format("NAME LIKE '%{0}%'", txtSearch.Text);