Every time I start PSNow, it sits on a loading screen for a couple of minutes before giving me the 'network unavailable' message. Based on network activity in task manager, the program isn't even attempting to connect to anything. I have the windows firewall and defender completely disabled, and I don't have a firewall of my own installed. I also have my PC plugged directly into my modem with all ports open in the router settings.
I solved it by disabling IPv6.
For those with the same problem:
Control Panel -> Network and Sharing Center -> Change Adapter Settings-> Right click-> Properties-> Un-check Intenet Protocol Version 6