https://jsfiddle.net/dgrogan/43da9xhL/

<table style="border-collapse:collapse">
  <tbody style="border:18px solid lightblue" id="section">
    <tr>
        <td style="width:50px;height:50px;padding:0px"/>
    </tr>
  </tbody>
</table>

Table is 86px wide. But changing #section's border to 4px changes the table width to 72px. (Blink only updates one side?)

Edge gets it right. Chrome and FF get it wrong in different ways.

Similar to  issue 609674 .