Investigate why confidential issues are not properly filtered

This package https://gitlab.com/gitlab-org/gitlab-ee/issues/11896 contains https://gitlab.com/gitlab-org/gitlab-ee/issues/6151 but it should not.

Another package https://gitlab.com/gitlab-org/gitlab-ee/issues/11891 contains https://gitlab.com/gitlab-org/gitlab-ee/issues/11649 but again it should not.

The policy file was https://gitlab.com/gitlab-org/quality/triage-ops/blob/master/policies/missing-categories.yml which utilized the Ruby condition to filter them, but doesn't seem to be effective for confidential issues.

This is weird because it's using labels API, and we only redact confidential fields in placeholders like {{labels}} but not any Ruby API.

Can it be possible that the GitLab API doesn't return the labels?