In our case, the menu_breadcrumb was also involved. Thank you texas-bronious!.
In addition to deploying the latest 2.0.x-dev, I had to apply this patch too: https://www.drupal.org/project/menu_breadcrumb/issues/3495164 🐛 Missing route cachability metadata. Active
Then the issue was resolved.
I hope this helps someone out there.
Testing 10.4.0 causes the same issue for us, and several projects currently on 10.3.x are impacted. Reverting to 10.3.10 resolves it. We can not proceed with the 10.4 upgrade until this is fixed.
Using patch from #184 does not seem to work on 10.3.2. Patch applies cleanly.
We are seeing this often on a new project that we are deploying with this purger. Is there a proper fix for this?