Update:
We thought we were misconfiguring or something, so we made a deep dive into the docs and related samples and saw nothing that indicated we were doing anything incorrect.
We tested on several different cPanel boxes with the same result. Past experience shows the amazing tech staff is quick to respond to bugs, so it made sense to post the issue in the bug reporting forum.
So, we then posted the info in the bug reporting forum, and it got promptly deleted, which was weird. We reposted it again, and that post was moved to the general forum and locked with no explanation other than to not repeat posts.
We didn't intend to repeat posts, but there is no mechanism to move or delete them.
At any rate, any assistance on the issue is welcomed.