Hello!
If your Ubuntu computer directly connects to the VPN you don't need any additional rule on the router. Error 111 (connection refused) hints to packets actively rejected by your system with a reset, so it is likely that the packets reach your computer indeed. Please make sure that the listening programs are really running and listening to the correct ports. Also make sure that such programs do not bind to the physical network interface, if a bind option is available in the settings. Last but not least, as far as it pertains to the torrent software, please re-check its configuration against our guide here: https://airvpn.org/faq/p2p/
If the problem persists, we strongly recommend that you open a ticket as well.
Kind regards