PHP Output from mysql database is blank - php

Question

I have this PHP page which accepts 3 items and stores into a database. The output of the results fetched from database is blank. I can see the records being saved in database via phpmyadmin. What's wrong with this code?
This is the code that displays results in a table.
// Add a shortcode to display the employee's attendance record
function attendance_record_shortcode( $atts ) {
global $wpdb;
$table_name = $wpdb->prefix . 'employee_attendance';
// Get the employee ID from the shortcode parameters
$atts = shortcode_atts( array(
'employee_id' => ''
), $atts );
$employee_id = $atts['employee_id'];
// Get the employee's attendance data from the database
$attendance_data = $wpdb->get_results(
$wpdb->prepare(
"SELECT * FROM $table_name WHERE employee_id = %d",
$employee_id
)
);
// Display the attendance data in a table
ob_start();
?>
<table>
<thead>
<tr>
<th>Date</th>
<th>Status</th>
</tr>
</thead>
<tbody>
<?php foreach ( $attendance_data as $attendance ) : ?>
<tr>
<td><?php echo $attendance->date; ?></td>
<td><?php echo $attendance->status; ?></td>
</tr>
<?php endforeach; ?>
</tbody>
</table>
<?php
return ob_get_clean();
}
add_shortcode( 'attendance_record', 'attendance_record_shortcode' );
This is the code that accepts input and saves data to database.
// Create the attendance page and display the attendance form
function attendance_page() {
global $wpdb;
$table_name = $wpdb->prefix . 'employee_attendance';
// If the form has been submitted, add the attendance data to the database
if ( isset( $_POST['submit_attendance'] ) ) {
$employee_id = $_POST['employee_id'];
$date = date( 'Y-m-d', strtotime( $_POST['date'] ) );
$status = $_POST['status'];
$wpdb->insert(
$table_name,
array(
'employee_id' => $employee_id,
'date' => $date,
'status' => $status
)
);
}
// Display the attendance form
?>
<h1>Employee Attendance</h1>
<form method="post">
<label for="employee_id">Employee ID</label>
<input type="text" name="employee_id" id="employee_id" required>
<br>
<label for="date">Date</label>
<input type="date" name="date" id="date" required>
<br>
<label for="status">Status</label>
<select name="status" id="status">
<option value="present">Present</option>
<option value="absent">Absent</option>
<option value="late">Late</option>
</select>
<br>
<input type="submit" name="submit_attendance" value="Submit">
</form>
<?php
}
phpMyAdmin Database Snapshot
Blank Output Page