Solution for "No" connection
1. Solution with public IP:
Open upnp on the router, or DMZ to the IP address of the qbittorrent host. You can search Baidu for these two settings!
2. Solution without public IP but with IPV6:
Open qbittorrent>Settings>Advanced>Optional IP address to bind to>Select all IPV6 addresses!
IPV6 test
Pay attention to whether the optical modem or router has a firewall. If yes, turn it off or set it to low!