Jim, I had a similar issue with my EQ6-R where the com port would show up but no communication seemed to take place. I was using EQMOD for connection and it ended up that I had to select the right 'Baud rate' in the EQMOD connection settings. I have absolutely no idea what this setting means, but changing it to 115200 made the connection actually work. I got this solution from the cloudy nights thread linked below, first post by MikeECha.
https://www.cloudynights.com/topic/6...-issue-solved/
I have no idea if this could be your issue, but thought it worth posting since it's similar to my issue where there com port would show but no communication happened.