Unable to add Docker Registry to Satellite 6.2

Issue

• Deployed Private Docker registry from scratch following the How do I setup / install a Docker registry? article, with no authentication and no TLS encryption (the same issue is observed even if authentication and/or encryption is enabled), both version 1 and version 2 API calls work fine (tested with curl, see Diagnostic Steps for details). Still, the following error message is displayed when we try to add it to Satellite 6.2:

  Could not create the registry: Unable to log in to this Docker Registry - Permission denied - connect(2) for "example.com" port 5001