select required not working in chrome

Question

A required select in Chrome isn't working (in Firefox it works). My code is:

<form id='form_tbl' action='include/value.inc.php' method="POST"><input type="hidden" name="quiz" value="1">
  <?php include "include/sel_tbl.inc.php"; ?>
</form>

and file sel_tbl.inc.php is:

<?php
...
echo "<table><tr><th>Name</th>><th>date</th><th>quiz</th><th>quiz2</th></tr>";
  while($row = $result->fetch_assoc()) {
        echo "<tr><td><input type='hidden' name='id_pers[". $row['ID'] ."]' value='". $row["ID"]."'>" . $row["Name"]. ' '. $row["lastn"]. "</td>";
        echo "<td><select name='nota_intr_1[". $row['ID'] ."]' required ><option disabled selected>nota</option>";
        for($i=1; $i<=10; $i++){ 
            echo "<option value='$i'>$i</option>\n";
        };
        echo "</select></td>";

        echo "<td><select name='nota_intr_2[". $row['ID'] ."]' required ><option disabled selected>nota</option>";
        for($i=1; $i<=10; $i++){ 
            echo "<option value='$i'>$i</option>\n";
        };
        echo "</select></td>";

        echo "<td><textarea name='sgs[". $row['ID'] ."]' form='form_tbl' maxlength='200' autocomplete='off' placeholder='test here...'></textarea></td></tr>";
  }
  echo '</table><button name="button_vot">send</button>';
?>

What is wrong with my code?

Answer 1

Required attribute causes a notification only if you are trying to submit an empty value from a required field. Give an empty value to the default selected option

<option value="" disabled selected>nota</option>

then it will notify, if a user does not select an option with a proper value.