So we have essentially reached a point where the issue seems to lie with Port Forwarding. Take a look at the post one of my team members helped another user with a very similar issue.
He mentions a free software tool which might be able to help you resolve your issue. This is honestly the extent of my knowledge with Swarm Agent, and the troubleshooting process. I wish I could offer more insight, but the application is not heavily documented, and sometimes errors occur which have no official/exact answer. It is going to take some diving into, a combination of settings, and a bit of Windows magic to get it to work as expected.
When you do find a resolution to your issue, we would greatly appreciate you sharing the process you took so we can document it as well. Let me know if you have other questions or additional comments.
Cheers,