Since this is a governmental application, the only ones who can provide support and status information are the developers from there the eBIRForms is listed for download.
I suggest reaching the developers and using their contact methods to get an overview about the current situation with the connectivity and servers, but before you do that make sure to add the program to exclusions and disable any programs that have to do with proxies. Check the Internet Options as well and disable any proxy setting that you might have set up. eBIRForms probably doesn't have support for this.