To prevent the highlight follow these steps:

Create a hidden page item to store the link column value, for example, I have a report on EMP table and the link column based on the EMPNO, so I created a hidden page item as P20_VEMPNO. Turn the value protected off for this hidden page item.

Specify a Staic ID to your link column, for example, sIDEMPNO.

CSS inline code:

.currentrow
{ 
 background-color: #eeeeee !important;
}

Now modify the JavaScript function as follows:

function irRowhighLight( pThis, pempno ){
  $('td').removeClass('currentrow');
  $(pThis).parent().parent().children().addClass('currentrow');
  var v_row = $(pThis).parent().next().html();
  $s("P20_VEMPNO", pempno);
}

Also, change the link attribute code as follows:

onclick=irRowhighLight(this,#EMPNO#);

In the above code I am passing the EMPNO column value to JavaScript function. If you column data type is varchar2 then specity the value in single quotes, for example, ‘#ENAME#’

Now create a dynamic action on interactive report for After Refresh event and add a True action to execute the JavaScript code. Add the following JS code in it:

$("td[headers=sIDEMPNO]").each(function(){
celldata= $(this).text();
if (celldata ==$v("P20_VEMPNO"))
$(this).parent().children().addClass('currentrow'); 
});

Save the changes and run the page to test.

Please let me know if still any issues.