json data not working on server

I retreived my json data using Jquery ajax. My data is:

[{"id":"2","checkNo":"74152","routingNo":"896523","accountNo":"741236","confirmAccountNo":"85263","custEmail":"avn@gmail1.com","custName":"jonita gandhi","custStreetAddress":"address2","custPhone":"78456","custCity":"city2","custState":"state2","custZipCode":"4123","amount":"71","memo1":"memo3","memo2":"","cmp":"support","bankName":"Federal Bank","bankAddress":"A-19, Golden avenue","bankCity":"Florida","bankState":"FE","isDeleted":"0","createdDtm":"2017-05-30 14:47:48","updatedDtm":null}]

On Jquery Success i hold the data in a variable

var jsonData = JSON.parse(JSON.stringify(data));

when i am trying to access checkNo. using jsonData[0].checkNo it yields undefined but when i check it using

console.log(jsonData)

It outputs data which is same as top.

Note: This problem yields only on server but it is working fine on my localhost.

Edit:

Here is my ajax call:

jQuery.ajax({
url: postUrl,
data:queryString,
type: "POST",
success:function(data){
    switch(action) {
      case "edit": 
      jsonData = JSON.parse(data); console.log(jsonData);
      //var jsssss = JSON.parse(JSON.stringify(data)); console.log(jsssss); 
      $("#custEmail").val(jsonData[0].custEmail);
      $("#custName").val(jsonData[0].custName);
      $("#custCheckNo").val(jsonData[0].checkNo);
      $("#edit_model").modal();
        break;
     //some more code
}
});