No one seems to have thought about the fact that most schools have been out for those three months. Not sure exactly how much of the traffic is high schoolers and college students cheating, but that could account for at least some of the loss in traffic.

Edit: missed a word

If you download a wireguard/openVPN conf file from Proton it will let you enable nat-pmp which is basically automatic port forwarding. It seems to work fine on a Linux machine running qbittorrent, but your case might be different.