How to disable the IPv6 on Windows
The Proton VPN Windows application(nowe okno) blocks all IPv6 traffic by default. We recommend disabling the IPv6 if you are using a manual VPN connection, such as IKEv2(nowe okno) or OpenVPN(nowe okno).
1) Open Network and Internet Sharing center via the System tray at the bottom-right corner.
2) Select Change adapter options.
3) Right-click on the network adapter you are currently using and select Properties.
4) Uncheck Internet Protocol Version 6 (TCP/IPv6) and save the change.
That’s it! In order to check whether IPv6 is disabled on your computer, you can do an IPv6 leak test here(nowe okno).
Related articles:
How to disable IPv6 on macOS(nowe okno)
How to disable IPv6 on Linux(nowe okno)