There are several signs that your VPN is blocked:
You can’t connect to your VPN. If you try to connect to your VPN and it fails, it's possible that your VPN is blocked.
You can’t access any websites or apps while connected to your VPN.
You see an error message when you try connecting to a website or service while on your VPN.
You notice a decrease in your internet speed when connected to a VPN. If your internet speed is slower when you're connected to your VPN, it's possible that your internet is being throttled.