javascript sends me to error instead of success {"readyState":0,"status":0,"statusText":"error"}

Question

I have the next javascript above. I need it to send the data to a model where is Insert the information on a database. It is doing staff fine and the information is recorded but instead of sending me to the success function it sends me to the error function.

I am geting in the alert(jqxhr): {"readyState":0,"status":0,"statusText":"error"}

and in the console.log(jqxhr): {readyState: 0, getResponseHeader: ƒ, getAllResponseHeaders: ƒ, setRequestHeader: ƒ, overrideMimeType: ƒ, …}

thrownError seems empty in the alert and the console.log

I can't tell what's wrong in the code.

function newBenefit(){
 var new_professional_id = document.getElementById("new_professional_id").value;
 var new_service_code = document.getElementById("new_service_code").value;
 var new_service_type = document.getElementById("new_service_type").value;
 var new_service_condition = document.getElementById("new_service_condition").value;
 var new_price_total = document.getElementById("new_price_total").value;
 var new_price_patient = document.getElementById("new_price_patient").value;
 var new_date_start = document.getElementById("new_date_start").value;
 var new_date_end = document.getElementById("new_date_end").value;
 $.ajax({
    type: "POST",
    url: "index.php?route=professionals/professional_edit_benefit_ajax",
    data: {
    action: 'new',
    professional_id: new_professional_id,
    service_code: new_service_code,
    service_type_id: new_service_type,
    service_condition_id: new_service_condition,
    price_total: new_price_total,
    price_patient: new_price_patient,
    date_start: new_date_start,
    date_end: new_date_end,
    },
    dataType: "json",
    fail: function( jqXHR, textStatus, errorThrown ) {
    alert(jqXHR);
    },
    error: function (jqxhr, ajaxOptions, thrownError) {
    console.log(jqxhr);
    console.log(thrownError);
    alert(JSON.stringify(jqxhr));
    alert(jqxhr.status);
    alert(thrownError);
    },
    success: function(data){
        console.log(data);
        if(data=="1"){
            //location.reload();
        }else{
            var continue_text='<?php echo $error_new_benefit_error; ?>';
            swal({
                type: 'error',
                title: 'Oooops...',
                text: continue_text,
            });
        }
    }
 });
}