@raphjd This is correct..... PIA is something different. They're based in the United States if I recall correctly which can be considered a red flag. Now.... That being said, they do support port forwarding, however they will randomize the port on each connection, so every time you connect, you must change the port settings in your torrent client.
PrivateVPN on the other hand from https://privatevpn.com/ will do the same on all servers, however for some servers, they support port forwarding for ALL ports, so you don't have to keep changing settings in your torrent client every time you connect.
As for ExpressVPN, they do support port forwarding, however in order to take advantage of this, you must install the VPN service on your router and setup the port forwarding within the router. Not all routers support this option, and by the same token, not all routers that support a VPN connection support ExpressVPN. This potentially makes it more expensive by having to upgrade your home network equipment and get into way more complicated setup to get it going.