[regression since 11.2] Uncaught TypeError: Cannot set properties of undefined (setting 'textContent') at ContextualModelView.render (contextual.js?v=11.2.2:356:29)

So far I see the code at core/modules/contextual/js/contextual.js:167 is attempting to get data-contextual-id elements that are not guaranteed to be there if these were relocated.

window.setTimeout(() => {
  initContextual(
    $context
      .find(`[data-contextual-id="${contextualID.id}"]:empty`)
      .eq(0),
    html,
  );
});

But this line hasn't changed in #3203920 so probably there is something more at play there.

Static patch for composer

My Drupal version is 11.2.0

I was able to reproduce the issue by following the same steps as mentioned above:

1. Added the below JS snippet manually in the contextual.js file to simulate block movement:

Drupal.behaviors.contextual_bug = {
  attach(context) {
    once('contextual_bug', '#block-olivero-views-block-who-s-online-who-s-online-block .block__content', context).forEach((element) => {
      // Move the who's online block content at the bottom, before body closing tag, replicating mmenu.
      const clone = element.cloneNode(true);
      document.body.appendChild(clone);
      element.remove();
    });
  }
}

2. Placed the Who's online block in the Content region.
3. Reloaded the page.
At this point, I saw the following error in the browser console:

Uncaught TypeError: Cannot set properties of undefined (setting 'textContent')

Then I applied the patch from #10 → and run composer install.
After applying the patch:

The error disappeared from the console.

###Patch / MR tested
Applied patch from #10

###Results:

JS console error disappeared after applying the patch.

### Environment
Drupal 11.2.x, PHP 8.3, MySQL 8.0, DDEV 1.25 (Docker + WSL2).

There are multiple places we call initContextual, we've updated one of those calls to check the element exists, but not the other.
But we've also updated the logic inside initContextual - I don't think we need both.
I'm inclined to make it check it from the outside rather than inside

Let's do that - thanks!