Can't invalidate Drupal's internal page cache

I can't seem to get updates to my XML feed to show up consistently for anonymous users of my site. I'll keep seeing the same data on pages using the XML view, unless I clear all of Drupal's caches.

I've tried configuring the cache for Views XML by adding this in my settings.php file for the site:
$settings['views_xml_backend_expire'] = 1

But that hasn't seemed to work.

One thing that has worked consistently is disabling Drupal's "Internal Page Cache" module, which I believe is a default module that's enabled on new Drupal 8 sites. That module will cache an entire rendered page for anonymous users.

From what I can tell, the Views XML Backend module doesn't have a way of invalidating that cache (which is implemented using Drupal's cache tag system). So, after I hit a page that's using the XML view as an anonymous user, both the Views XML cache will get built, and this internal page cache; but Drupal will keep giving the user the internal page cache until it's cleared.