Jqgrid - only one search option appears in the header column - jqgrid

Question

I am working in a Jqgrid and have encountered a problem. I have looked at many examples and read alot of documentation but can't seem to determine why only 1 search option appears in the column header as opposed to the others such as "ge" "le" "eq" etc?
This is my code:
jQuery("#jQGridDemo").jqGrid({
url: 'http://localhost:58404/JQGridHandler.ashx',
datatype: "json",
colNames: ['Property ID', 'Property Ref', 'Short Address', 'Scheme Code', 'Scheme Name', 'Property Type', 'Tenure Type', 'Status'],
colModel: [
{ name: 'PropertyID', index: 'PropertyID', width: 70, align: "left", searchoptions: {sopt: ["ge","le","eq"]}, sortable: true},
{ name: 'PropertyRef', index: 'PropertyRef', width: 75, align: "left", stype: 'text', sortable: true},
{ name: 'ShortAddress', index: 'ShortAddress', width: 200, align: "center", search:true, stype: 'text', searchoptions: {sopt: ["cn","ge","le","eq"]}, sortable: true},
{ name: 'SchemeCode', index: 'SchemeCode', width: 80, align: "center", sortable: true },
{ name: 'SchemeName', index: 'SchemeName', width: 80, align: "center", stype: 'text', sortable: true },
{name: 'PropertyType',width: 80, align: "center",},
{ name: 'TenureType', index: 'TenureType', width: 80, align: "center", sortable: true },
{ name: 'Status', index: 'Status', width: 75, align: "center", sortable: true },
],
beforeProcessing: function (data) {
//Create the filters
getDropDownValues(data, 'PropertyType')
getDropDownValues(data, 'TenureType')
getDropDownValues(data, 'Status')
$(this).jqGrid('destroyFilterToolbar')
.jqGrid('filterToolbar', {
stringResult: true,
searchOperators: true
});
},
onSelectRow: function(id){
if(id && id!==lastsel2){
jQuery('#jQGridDemo').jqGrid('restoreRow',lastsel2);
jQuery('#jQGridDemo').jqGrid('editRow',id,true);
lastsel2=id;
}
},
height: 'auto',
width: 'auto',
rowNum: 30,
editable: true,
mtype: 'GET',
loadonce: true,
rowList: [30, 40, 50],
pager: '#jQGridDemoPager',
sortname: 'PropertyId',
viewrecords: true,
sortorder: 'desc',
caption: "Property Details",
editurl: 'http://localhost:58404/JQGridHandler.ashx'
});