Are you absolutely positive you selected the correct interface? 'Cause if you’ve been using lo
eth0
or basically anything that is clearly your default interface then you haven’t been using the right one. Typically on, Windows for example, the interface for your VPN is named accordingly. AKA: your VPN provider is the name of the interface. Whereas on Linux and Mac you’ll have to verify the network interfaces yourself via the Terminal.
When, binding QBT to your VPN interface what it does is it disallows QBT from connecting to the internet without the specific VPN interface. AKA, when the VPN drops it should not be able to access the Internet because the network interface that was bound to it (the vpn) is no longer accessible (no internet connection).
If you don’t mind me asking, what VPN are you using? And most importantly have you taken a look at this guide: https://old.reddit.com/r/VPNTorrents/comments/ssy8vv/guide_bind_vpn_network_interface_to_torrent/
The guide linked above is a tremendous help in ensuring you’re binding to the correct interface. Another potential cause of the IP leak is the use of IPV6 addresses In Settings>Advanced for Optional IP address to bind to
change “All addresses” to “All ipv4 addresses”
Unless you’re using a VPN that actually encrypts ipv6 network traffic, then you’re bound to leak your ipv6 address, therein leaking your real-world IP address. -Which, a surprising amount of VPN providers do NOT provide protection for. In the event that you’ve bound QBT to the correct network interface, it’s likely that this is the cause of the leak.
And most importantly, depending on the VPN you’re using it could very well just be that they don’t support P2P (torrenting) connections and are purposefully leaking your real IP because they fucking hate you lol. In any case verify that your particular VPN provider actually allows P2P connections on their servers. You can pretty easily do this by looking up your VPN provider + qbittorrent, torrenting, or P2P connections/servers in NOT GOOGLE because they will purposefully obscure results like that. Use duckduckgo dot com to find results…
For reference, there’s only a handful of trustworthy VPN services that allow P2P connections and even fewer that allow P2P connections and port forwarding via NAT. From what I’ve managed to find from both user review and personal review of their privacy policy, logs policy, services provided, etc the only worthwhile VPN providers for torrenting are; AirVPN, Windscribe, ProtonVPN & Mullvad. Of course they all have their pros and cons, but one thing to point out is that AirVPN is NOT beginner friendly in the slightest in any way shape or form. They’re quite possibly the cheapest option in the list but unless you have a firm grasp of networking and basic IT stuff then you’ll have a horrible time trying to set it up for torrenting as literally every single guide for QBT on the forum is severely outdated or very specific to that particular user’s use-case. Meaning it will very likely not suit your use-case.
Whereas, Mullvad, ProtonVPN, & Windscribe are incredibly user friendly. Basically one-and-done setup. Though, it’s highly recommended to look through the various options available to you to better configure it for torrenting and overall security/privacy.
TLDR: You may not be using the correct network interface for your VPN. Your VPN may not support ipv6 (meaning that your ipv6 address is in use and NOT encrypted at any given time), meaning that it is leaking your ipv6 address, therein leaking your real address. Or it could simply be that your particular VPN provider doesn’t support P2P (torrenting) network traffic and is straight up dropping your VPN connection or purposefully leaking your real IP due to them absolutely despising you.