Error 6021 is a general server timeout error that occurs when it takes too long to receive a response from the server when attempting to connect. This usually can be caused by latency from your local network or interference from antivirus/firewall software.
Please first refresh your network by unplugging your modem/router for 30 seconds and plug it back in. Next, temporarily disable any antivirus/firewall software you are running and attempt your connection again. If the issue persists, we would recommend attempting to connect using an alternate protocol such as IKEv2 to see if you experience similar issues.
Our support team can work with you further to determine if the error is being caused by latency or other issues.
If you need any further assistance, please contact our 24/7 Customer Success Team, who would be glad to assist.