Jquery ajax – AJAX call only calls data for one dropdown list instead of two dropdown lists

I am new and still learning on AJAX call and I cant figure out why my AJAX call only calls data for one dropdown list only. Okay, the scenario is that I have 3 dropdown list in my form which are to select a doctor, display consultation fee and provide list of appointment date. The problem I’m facing is that when a doctor is selected in the doctor dropdown list, the AJAX call will only loads the data for the appointment date dropdown list. It didn’t load the consultation fee.

Here are my code for doctor, consultation fee and appointment date dropdown list:

<div>
  <label>Select Doctor</label>
  <select name="doctor" id="get_doctor_name" onchange="getfee()" autocomplete="off" required>
    <option hidden value="">Select Doctor</option>
  </select>
</div>

<div>
  <label>Consultation Fee</label>
  <select name="fees" id="get_doctor_fee" autocomplete="off" readonly>
  </select>
</div>

<div>
  <label>Appointment Date</label>
  <select name="appdate" id="get_date">
  </select>
</div>

UPDATED: Here are the script for the AJAX call with function getfee() and getdate():

<script>
      //function for fee details
      function getfee() 
      {
        $("#loaderIcon").show();
        jQuery.ajax(
        {
          url: "getfee.php",
          data: {doctor : $("#get_doctor_name").val()},
          type: "POST",
          success: function(data) 
          {
            $("#get_doctor_fee").html(data);
            $("#loaderIcon").hide();
          },
          error: function() {}
        });
      }

      //function for appointment date details
       function getdate() {
       $("#loaderIcon").show();
       jQuery.ajax({
       url: "getslot-date.php",
       data: {doctor : $("#get_doctor_name").val()},
       type: "POST",
       success: function(data) {
         $("#get_date").html(data);
        $("#loaderIcon").hide();
       },
       error: function() {}
    });
 }
    </script>

Here are code in getfee.php in the AJAX call script:

<?php
include('incl/connection.php');
if(!empty($_POST['doctor'])) 
{
    $doctor =$_POST['doctor'];

    $sql = "SELECT D_FEES FROM tbldoctor 
            WHERE D_ID=:doctor";

    $query = $dbh->prepare($sql);
    $query->bindParam(':doctor',$doctor,PDO::PARAM_STR);
    $query->execute();
    if (!$query->execute()) {
    print_r($query->errorInfo());
}
    $results=$query->fetchAll(PDO::FETCH_OBJ);
    $cnt=1;
    if($query->rowCount() > 0) 
    {
        foreach($results as $results) 
            { 
               echo '<option readonly value="'.htmlentities($results->D_FEES).'">'. htmlentities($results->D_FEES).'</option>';
            }
    }
    else
    {
       echo '<option value=""> No Doctor in this specilization</option>';
       echo "<script>$('#submit').prop('disabled',true);</script>"; 
    }
}
?>

Here are code in getslot-date.php in the AJAX call script:

<?php
include('incl/connection.php');
if(!empty($_POST['doctor'])) 
{
    $doctor =$_POST['doctor'];
    $sql = "SELECT T_ID, T_DATE, T_TIME FROM tbltimeslot 
            WHERE D_ID=:doctor AND A_ID IS NULL";

    $query = $dbh->prepare($sql);
    $query->bindParam(':doctor',$doctor,PDO::PARAM_STR);
    $query->execute();
    if (!$query->execute()) {
    print_r($query->errorInfo());}
    $results=$query->fetchAll(PDO::FETCH_OBJ);
    $cnt=1;
    if($query->rowCount() > 0) 
    {
        foreach($results as $results) 
        {
            echo '<option value="'.htmlentities($results->T_ID).'">'.htmlentities($results->T_DATE).' @ '.htmlentities($results->T_TIME).'</option>';
        }
    }
    else
    {
       echo '<option value=""> No available date</option>';
       echo "<script>$('#submit').prop('disabled',true);</script>"; 
    }
}
?>

And below are the table for tbldoctor and tbltimeslot:

CREATE TABLE `tbldoctor` (
  `D_ID` int(11) NOT NULL,
  `D_SPECILIZATION` varchar(255) NOT NULL,
  `D_NAME` varchar(255) NOT NULL,
  `D_FEES` varchar(255) DEFAULT NULL
)

CREATE TABLE `tbltimeslot` (
  `T_ID` int(11) NOT NULL,
  `T_DATE` date NOT NULL,
  `T_TIME` time NOT NULL,
  `D_ID` int(11) NOT NULL,
  `A_ID` int(11) DEFAULT NULL
)