From what I understand you have opened up a socket listener 20220/TCP on your router, but that won't work - you need to actively create a connection to the pypilot's 20220/TCP socket. This would require specifying pypilot's IP address. It does not seem to me that it can be done with that router.
However, if you have OpenCPN, you can use that to forward the NMEA messages to pypilot. For that, you first need to configure your pypilot with a fixed IP address through its web interface, if you haven't already done so. Then you can either create a data connection in OpenCPN to that IP address, output to tcp socket 20220, with at least RMC and APB messages for GPS mode and MWV messages for Wind modes. This allows you to troubleshoot using OpenCPN's NMEA debug window. Alternatively, you can check Forward NMEA in the OpenCPN PyPilot plugin configuration.
However, if you have OpenCPN, you can use that to forward the NMEA messages to pypilot. For that, you first need to configure your pypilot with a fixed IP address through its web interface, if you haven't already done so. Then you can either create a data connection in OpenCPN to that IP address, output to tcp socket 20220, with at least RMC and APB messages for GPS mode and MWV messages for Wind modes. This allows you to troubleshoot using OpenCPN's NMEA debug window. Alternatively, you can check Forward NMEA in the OpenCPN PyPilot plugin configuration.