You are using the demo page provided and it is reproducing the same error. If you enter in a search value; for example "dia" and hit enter it will filter just fine; however as soon as you click on a column to sort; the search box get populated with filtering text.

steps to recreated. 1. Click the page:

https://www.koolreport.com/examples/reports/datagrid/datatables_searching/

1. Enter dia in the search box;
2. click on a column to sort
3. search box get strange text.