qBittorrent network interface bind not working?

I am using ProtonVPN, and have (or so I thought) set up qBittorrent to bind to the network interface that ProtonVPN is using (tun0). The connection symbol turns red if I turn off the VPN, and downloads will stop. However, when checking the torrent address on ipleak.net, it seems that this bind is not working properly - my real...