Were you trying to install a VPN kill-switch in iptables or something and mess up somehow? I did have an issue similar to this once, where I was firing up my VPN, not realizing it wasn’t allowing multiple clients, and so my initial client would get kicked off and I’d have to reauth on the VPN to get connected again – in my case I was split-tunnelling a wireguard connection, but could that be happening? Are you firing up Qbittorrent with some sort of VPN scripts and getting kicked off of your normal VPN connection?