Recently a security issue became public that allows owners of websites to find out your real IP address even when you use a VPN service.
Since version 1.4.13 of Online Shield VPN, you can prevent this from happening by opening the Online Shield settings and activating the option "Prevent WebRTC IP leak".
You can check whether your IP is leaked here: https://diafygi.github.io/webrtc-ips/
After establishing a VPN connection and refreshing the test page, only the IP adress of the VPN Server should be displayed under "Your public IP addresses".
Your real IP address should not be displayed at all as long as the VPN connection is active.