You could share your compose file.
Can you exec into the qBittorrent container to ensure internet connectivity works? For example attempt to ping 9.9.9.9 or curl duckduckgo.org.
If it doesn’t work, try the same from the gluetun container directly.
If it doesn’t work from the gluetun container, there likely is an issue with the Wireguard configuration.
You could share your compose file. Can you exec into the qBittorrent container to ensure internet connectivity works? For example attempt to ping 9.9.9.9 or curl duckduckgo.org. If it doesn’t work, try the same from the gluetun container directly. If it doesn’t work from the gluetun container, there likely is an issue with the Wireguard configuration.