Me too. Are you able to connect to blue iris web server from the work WiFi? I'd bet they are blocking it.
Are you sure you verified you are able to access the WEBSERVER login page? When I open chrome browser on my connected device, on work network, then enter the address to my BI webserver. I get a warning stating this site can't be reached and it times out. This was the issue for me. http://ip-address:81 Try it through a browser, not rdc.
Thank you for clarifying. There must be something else in your case. Good luck.
Are you able to connect to your blue iris web server on your work network via the actual IP, NOT the DDNS. I noticed my work wifi is able to connect via my ddns, but my actual ip is blocked. Also when I look at the network traffic for the push notifications from blue iris the URL for the image is the actual ip address, not the ddns. This is why it was blocked and I could not figure it out. Id say try your actual ip address to see if THAT is blocked instead of your ddns.
Good luck!