This page would list all know questions and potential problems, with possible answers or remedies.
In 2018, IBM Cloud moved to a "Lite" account. If you have an old "Trial" account that expired after 30 days you should go to https://cloud.ibm.com/registration/startUpgradeToLite to freely convert your account to a "Lite" account.
Ask for whitelisting, or use your own smart phone with data plan (do not use local WiFi).
Try restarting the VPN pod with the following command (log in to the environement using CLI token):
kubectl delete pod -l app=vpn -n kube-system --wait=false
Try restarting the VPN with the following command:
kubectl delete pod -l app=vpn -n kube-system --wait=false
If that doesn't work please rebuild a cluster, or ask to get a new cluster.