CF Upgrade Issue while binding dropdown value to a bind in cfgrid - coldfusion

Question

We are upgrading our CF Server 9 to latest CF 2018. And i am facing bind issue between dropdown selected value and cfgrid bind.
There is dropdown just above the cfgrid that is set empty at first and has values listed of a query, and just below is a grid that binds the dropdown selection value to the query that is fetched.
At first as empty is selected it would not fetch records and grid would be empty. Also the bind URL is correctly formed.
http://127.0.0.1:8501/app/dummy.cfm?&DbFunc=getRecords&SrcID=&newSrcID=&flt_nm=&flt_iv=&flt_ct=&flt_sc=&flt_in=&pageSize=174&_cf_ajaxproxytoken=6D89B1BFAE8D17997E5A&_cf_clientid=1AFC4F973849FBAE6EAAA465492A0E0B&_cf_rc=0&_cf_nodebug=true&_cf_nocache=true&returnFormat=json&_dc=1549690631545&start=0&limit=174&page=1&sortCol=&sortDir=ASC
But next when i select the dropdownto a new value the URL is formed in this way.
http://127.0.0.1:8501/app/dummy.cfm?&&DbFunc=getRecords&SrcID=Test&SrcID=&&newSrcID=Test&&flt_nm=&&flt_iv=&&flt_ct=&&flt_sc=&&flt_in=&pageSize=174&_cf_ajaxproxytoken=6D89B1BFAE8D17997E5A&_cf_clientid=1AFC4F973849FBAE6EAAA465492A0E0B&_cf_rc=0&_cf_nodebug=true&_cf_nocache=true&returnFormat=json&_dc=1549690634739&start=0&limit=174&page=1&sortCol=&sortDir=ASC
As you can see the SrcID is getting appended twice for first time empty and next adding the selected value. I am receiving this as a comma separated value on my next page which is incorrect.
the query params are getting added as a separate instead of overwiting the old params.
The SrcID param is defined at top and next is the dropdown and directly at the bottom is the cfgrid where it is used in bind.
Thanks in advance
Here is a sample code below
<cfajaximport tags="cfform, cfinput-datefield, cftooltip, cfwindow, cfgrid, cfmessagebox">
<script type="text/javascript" language="javascript">
function doRefresh(form){
cSrcID = form.SrcID.options[form.SrcID.selectedIndex].value;
console.log('me'+cSrcID+'u');
cSortFld = '';
form.newSrcID.value = cSrcID;
}
// get client area of the browser
var cliWt = getClientWt(); // client width
var cliHt = getClientHt(); // client height
// set grid dimensions scrWidth, scrHeidht
var gWt = 34; // right margin
var gHt = 180; // top margin
var minWt = 500; // min width of the table
var minHt = 280; // min height of the table
var scrWidth = cliWt - gWt;
var scrHeight = cliHt - gHt;
if (scrWidth < minWt) scrWidth = minWt;
if (scrHeight < minHt) scrHeight = minHt;
// set winEdit popup window dimensions
var popwinWt = 1150;
var popwinHt = 680;
var bResizePopup = 0;
if (popwinWt > cliWt) {
bResizePopup = 1;
popwinWt = cliWt - 10;
}
if (popwinHt > cliHt) {
bResizePopup = 1;
popwinHt = cliHt - 10;
}
// set winEdit2 popup window dimensions
var popwinWt2 = 900;
var popwinHt2 = 510;
var bResizePopup2 = 0;
if (popwinWt2 > cliWt) {
bResizePopup2 = 1;
popwinWt2 = cliWt - 10;
}
if (popwinHt2 > cliHt) {
bResizePopup2 = 1;
popwinHt2 = cliHt - 10;
}
// set winEdit3 popup window dimensions
var popwinWt3 = 800;
var popwinHt3 = 550;
var bResizePopup3 = 0;
if (popwinWt3 > cliWt) {
bResizePopup3 = 1;
popwinWt3 = cliWt - 10;
}
if (popwinHt3 > cliHt) {
bResizePopup3 = 1;
popwinHt3 = cliHt - 10;
}
</script>
<cfset maxRowCnt = 174>
<!--- Set Grid default params --->
<cfparam name="page" default="1">
<cfparam name="pageSize" default="#maxRowCnt#">
<cfparam name="cfgridsortcolumn" default="">
<cfparam name="cfgridsortdirection" default="">
<cfform name="mainForm">
<cfoutput>
<br /><cfselect name="SrcID" title="Select a Source" style="width:200px;" onchange="doRefresh(this.form)">
<option value="">Select a Data Source</option>
<option value="Test">Test</option>
</cfselect>
<input type="hidden" name="newSrcID" value="">
<input type="hidden" name="flt_nm" value="" />
<input type="hidden" name="flt_iv" value="" />
<input type="hidden" name="flt_ct" value="" />
<input type="hidden" name="flt_sc" value="" />
<input type="hidden" name="flt_in" value="" />
</cfoutput>
<!--- Main Grid title="List of Records" --->
<cfgrid format="html" name="mainGrid" sort="yes" style="border:1px solid ##002D96;" visible="no" pagesize="#maxRowCnt#" maxrows="#maxRowCnt#" vspace="20"
striperows="yes" striperowcolor="#gcGray#" bgcolor="#gcRowWhite#" colheaderbold="yes" colheadertextcolor="##464646" width="scrWidth" height="scrHeight"
selectcolor="##FFCC99" selectmode="edit" selectonload="false" picturebar="yes" gridlines="yes" autowidth="yes"
bind="url:dummy.cfm?DbFunc=getRecords&SrcID={SrcID}&newSrcID={newSrcID}&flt_nm={flt_nm}&flt_iv={flt_iv}&flt_ct={flt_ct}&flt_sc={flt_sc}&flt_in={flt_in}&page={cfgridpage}&pageSize={cfgridpagesize}&sortCol={cfgridsortcolumn}&sortDir={cfgridsortdirection}"
onchange="url:dummy.cfm?DbFunc=doNothing&action={cfgridaction}&row={cfgridrow}&changed={cfgridchanged}"
font="arial" fontsize="14px" colheaderfont="arial" colheaderfontsize="14px" textcolor="##464646">
<cfgridcolumn name="si_id" header="ID" display="yes" select="no" width="45"/> <!--- FDB-164 --->
</cfgrid>
</cfform>
On the dummy.cfm
returns a query data in JSON format based on the Src Id selected