<button popovertarget="popover">Click me</button>
<div id="popover" popover>
  <div class="tether"></div>
  <p>I'm a popover, with a thether.</p>
</div>

Where .tether is anchor positioned to the button (https://codepen.io/jpzwarte/pen/MYwEaVm).

The issue is that in the accessibility panel of the Chrome devtools, .tether is shown as the "details" relationship of the button.

This seems wrong. If there is a details property, then i would expect it to point to the popover, not the tether.