How to use a VPN client on Your Windows VPS / Windows Server
If you have problems in connecting to your VPS using VPN, then it means that your IP change is not being accepted by your VPS, so it is restricting your connection. You can solve this issue by setting up a dynamic DNS host and connecting to the static dynamic DNS hostname instead of changing your IP.
Steps to follow:
Then, download and install the No-IP client for your operating system and configure it for DNS host
Now, the DynDNS-client will refresh your hostname automatically with your current IP.
Now, when you are connecting to your VPS, you need to connect with its hostname rather than its IP.