Results of embedded views with exposed filters that fail validation get cached for all requests

Patch attached

Thanks for looking into this @jerdavis,

Looking at a couple of the views that I know were affected, in both cases "Use AJAX" was set to "Yes" and "Caching" to "Tag based".

I did notice that although the individual elements had the url.query_args context in $elements[$delta]['#content']['#cache'], debugging via xDebug it seemed that the cache information added at that level was not bubbling up to the entity cache or page cache but cache information added via $elements['#cache'] was.

Basically, the code that calls ViewfieldFormatterDefault::viewElements() is ultimately called from these lines in Drupal\Core\Entity\Entity\EntityViewDisplay::buildMultiple():

          $build_list[$id][$name] = $field_access->isAllowed() ? $formatter->view($items, $view_langcode) : [];
          // Apply the field access cacheability metadata to the render array.
          $this->renderer->addCacheableDependency($build_list[$id][$name], $field_access);

What is returned from $formatter->view($items, $view_langcode) appears to contain no information about the #cache array of each field value so nothing useful is getting passed through to $this->renderer->addCacheableDependency().

Maybe we should merge each field value instance's cache tags and cache contexts (and max age?) into the field level cache array.

Both Internal Dynamic Page Cache and Internal Page Cache are enabled, Browser and proxy cache maximum age is set to one month. Not sure if it's a factor but the viewfield is attached to a paragraph type and the paragraph is in a paragraph field on a node.

I've looked though the theme layer and custom modules to see if we've done anything out of the ordinary in respect to the rendering of the node, paragraph, field or view and haven't found anything.

Good work, thanks for that. Odd that the issue only appears when there's an alias! I was trying to replicate it on a vanilla install today but failed, probably because of I didn't set an alias.