A fully VPN’ed family member got hit with an automated copyright strike and when looking into how it happened I found out that using the default qBittorrent config with a killswitch-enabled ProtonVPN meant that the home IP address was being leaked. I verified it through a few tools, including ipleak(dot)net’s fake magnet link feature which showed both the VPN and home IPs when connected. I’m at best a tinkerer so I’m not sure if this is a Proton-exclusive problem at all, or if the killswitch useage is even relevant, but that’s what they were using and figured this all might be worth mentioning since it was certainly a shock to us and not something we’ve seen brought up before.
The solution was to change which network interface qBittorrent was set to use via “Tools > Preferences > Advanced > Network interface”. Which one to pick will depend on the protocol you’re using in Proton’s client, but unless you’re confident in what you’re doing I’d recommend testing each with the ipleak(dot)net (or similar) torrent tool until you’re only seeing the VPN IP show up.
Hope this is useful! (and not common knowledge that we were just wildly ignorant of)
Binding the interface is definitely the recommended way to go about it, it was in some manual when I first informed myself about torrenting. But it’s not required and easy to miss if you don’t consume correct resources, it’s not obvious.
Iduno how we both managed to miss that part over all these years. Neither of us are new to any of this and we’re both privacy fanatics… but somehow it slipped through the cracks. Enough tech-shame for a lifetime, condensed and consumed in a singular moment.