Please make sure you have added the following exceptions to your windows server firewall on your DMZEdge server:
port 45000 for your dmzedge server
port 20/21 for ftp (20 - control, 21 - data)
port 22 for sftp (if using sftp)
port 989/990 for ftps (989 - control, 990 - data)
Make sure your BGR (border gateway router) and Firewall have rules allowing access between your Titan server IP and your DMZEDGE server IP on port 45000 and that you have server connectivity. (Can you ping back and forth)?
If all else fails, restart your Titan Server that is connecting to your DMZEdge server (not just the Titan service).
See our QuickStartQuickStart on configuring firewall security with Titan and Cornerstone: https://southrivertech.com/wp-content/uploads/qs_Cornerstone_Firewall.pdf