dhtmlxGrid loading JSON with link and searching

I am loading JSON with a link in the first column. Before I added the link, that column was searchable using the form code below. Now that I am loading the JSON with a link it is no longer searchable. Any ideas why?

<form id="search">
<input type="button" name="a11" value="&#xf021" id="a11" onclick='myGrid.filterBy(1,document.getElementById("a12").value);'>
<input type="text" name="a12" value="" id="a12" placeholder="Seach by Campaign Name">

Here is the rendered output from the grid, an example from column A:

<td valign="middle" align="left" title="null"><a onclick="(_isIE?event:arguments[0]).cancelBubble = true;"></a><a href="campaign.php?id=126275" title="null">Vishnu Radius Campaign using new modal</a></td>

Here is a sample of the JSON:

[{"camp_campaign_id":"11856","camp_campaign_name":"<a href=\"campaign.php?id=11856\">proof test<\/a>","camp_customer_id":"10356","camp_startdate":"2016-05-26 00:00:00","camp_duration":"10","camp_status":"Complete"}]


Please, try to add:
in the init of your grid.