Find ID of next instance of a specific class

I’m trying to find the ID (test1, test2, test3 etc..) of the next instance of a specific class (findMe).

Here is my code:
HTML:

    <div class="container">
  <table>
    <tr id="test1" class="findMe">
      <td>
      <button class="next">Next</button>
      </td>
    </tr>
    <tr id="test2" class="findMe">
      <td>
      <button class="next">Next</button>
      </td>
    </tr>
  </table>
    <div id="test3" class="findMe">
    </div>
  </container>

JS:

$(".next").click(function() {
console.log($(this).parent().closest(".findMe").next().attr('id'));
})

I can find the ID “test2” but not “test3”. Why?