It's strange that it did work fine a day ago but then the issue appeared. We didn't change anything on our side and players are playing as usual without any problems. So we can assume something changed in your PC or router configuration (firewall, antivirus, router's firmware).
Please try to temporary disable the Firewall to ensure it's not related to the issue.
Please also check the antivirus software settings (if you use any).
If nothing helps please provide the latest client log file from <Documents>\AtomicTorchStudio\CryoFall\Logs
Regards!