The most common reason for VPN disconnection is your Wifi network. If you are connecting to the internet via Wifi, and then connecting your VPN, you’re likely to experience drop-outs. This is because Wifi isn’t continuous. It may appear to be, but occasionally it will drop out – just for a split-second. That split-second is enough to drop your VPN connection.
How can you ensure VPN continuity? If your PC is close enough to your modem/router, then connect them both with a network cable. This will provide internet via cable, not wifi, and your VPN connection will be much more robust.