PTT by RTS is equally available on the audio socket regardless of the configuration of the serial port. For good measure it’s worth trying the same on Windows machine as demonstrated in the troubleshooting video. That will help rule out the hardware altogether so you can focus strictly on the software configuration.
Well, I was never able to get the unit working on either Linux or windows and troubleshot it down to what i believed was the device itself. So I ordered a lite, and when that came in today, everything popped up and start working almost immediately (other than adjusting com port, etc). Sent a message via the digirig co tact form to see if I can send it back and have them tell me how much it would cost to repair or replace. Dont know if I inadvertently dis something to it, but don’t know what that could possibly be.