It seems pretty clear that contacts tagged with "NO BULK EMAILS (USER OPT OUT)" are still receiving bulk email. I see many contacts who continue to be listed as receiving bulk emails in the mailing tab and the activities tab. We tag contacts as No Bulk Emails both internally, as well as people using the self-service link at the bottom of emails. We have been using this Civi install for many years and I feel like this feature used to work fine.
Is anyone else experiencing this? Is there a setting I should check? Any helpful advice would be appreciated.
We have a standard install in Debian, Drupal 7.65, CiviCRM 5.10.3.