Hello John and thank you for posting to the forum.
Can you verify that the amphenol cable connectors are firmly seated on both the ADTRAN unit and the 66-block? If the cabling is secure, we will need to look at a debug to determine if the ADTRAN is seeing the phone go offhook on that FXS port. You can access the ADTRAN by a console connection, SSH, or Telnet - we want to be in the command line.
Once you are in enable mode, run these debugs together:
debug interface fxs
debug voice verbose
Now go offhook on the port you are working on. We should see messages indicating that the phone/test set is on/off-hook. Lets verify the ADTRAN is seeing the on/off-hook states and then we can go from there. Also, feel free to attach your conifg but remove any sensitive information like IP addresses, passwords, etc.
I just did a shut no shut on the FXS port and it came back as a usable port.... nothing in the logs suggested a problem. Ie cable issue etc Sorry so late but I have been busy!