Thanks @pfaffman
I just rebaked all posts and found no change. After rebaking, I created some test posts again. To re-cap what I’m seeing (and looks like what @Richie sees)
-An image in a post correctly links to the CDN for the image displayed inline in the post.
-For the image however, the “download” link (lower right when viewing the image full size), links to a short-url, which redirects to my S3 bucket (not the CDN)
-For a PDF upload, the link links to a short-url, which redirects to my S3 bucket (not the CDN).
It appears that any time a short-url is used, the CDN is not used in the redirection.
For my Discourse setup, I am using S3 for both uploads and backups. I have not moved all of my existing uploads to S3 yet (will do once I get over this issue). I also do not have secure uploads enabled.
Thanks!