Your browser is likely leaking your IP address, even if connected to a VPN
Browsers support a peer-to-peer API called WebRTC. Its purpose is to improve user experience with communication applications, however, it leaks your private and public IP address even when connected to a proxy or VPN.
After you fix the problem, check this WebRTC Leak Test tool. Under "IP Address Detection", you should see "n/a" instead of any IP addresses.
Here's an article by torrentfreak.com to learn more about the WebRTC flaw.