The KISS Port number should be left at 0.
From the logs there is no response from the Winlink RMS to your connection request. So either the Winlink RMS is not hearing you, or you are not hearing the response.
Until that initial connection is made there can be no attempt to exchange messages. So the tricky bit is working out where the problem lies.
Its obviously tricky to diagnose connection problems at a distance, but I would suggest that you try the following:
* first check that you are transmitting on the correct band. You have this configured in WoAD, but you should confirm that you have the RMS frequency programmed for the same band on the TH-D74. Feel free to send a picture of the D74 screen during an active session if in doubt
* check that the D74 is actually transmitting (LED "A" or "B" on top of radio lights up red while outgoing packet is transmitted)
* if that looks okay, use a second radio to listen in on the RMS frequency and confirm that you can hear the outgoing packet.
* if you can hear the outgoing packet can you also hear the packet in response from the Winlink RMS
* if you can hear the incoming packet do you see the "A" or "B" LED turn green while the incoming packet is being received by the D74
Others may have useful tips as well, but that is all I can think of.
All the best,
Andrew
VA7YAA