I appreciate your help. After many decades of working in IT development and support, vague questions and responses create more work than necessary. Based on your experience, I think you would agree.
The CDN is only set up for the S3 bucket.
I did check the CDN logs for the Discourse IP related to the 403 errors before submitting the original topic. It was not in the log files.
Based on your comments, I went back and reanalyzed the logs. After reviewing the largest IP offenders, I found that the top couple are gateways for the hosting company.
The challenge is that I do not want to keep track of the Digital Ocean’s gateway IP addresses so my Discourse server can display images correctly.
Thank you for the assist.