amp-list fallback only loading on page resize

Question

I have the following amp-list in an AMP mail I'm working on. I set the amp-list src to an endpoint that doesnt exist in order to see the fallback. The issue is that the fallback is not being rendered after the request has failed, but it does show if I resize the browser for some reason.

This is the AMP email -

<amp-list
  id="outterList"
  single-item items="." 
  src="https://b56124055d2a.ngrok.app/notfound"
>
  <div placeholder style="min-height:200px"></div> 
  <div fallback> 
    <div style="overflow: auto; display: block;">
      <div style="height:500px;background:blue">asdasd</div>
      <div style="height:500px;background:red">asdasd</div>
    </div>
  </div>
  <template type="amp-mustache">
    test
  </template>
</amp-list>

How can I make it so that the fallback content is render properly?

I tries using css with overflow: auto; display: block.

EDIT: adding this video better illustrate the issue