Eric,
I understand you are able to start the RDz UT instance.
In the Start System Z we have two x3270 commands to open two X3270 terminals.
In your post you say you get two terminals with this message
Instance: IBMSYS1
Host-IP: 192.168.1.129:3270, Client-IP: 192.168.2.24
Term-type: IBM-3278-2-E, LU-name: tso, Device-addr: 0701
Can you please make sure that both of the terminals have the Device-addr set to 0701?
It should be Device-addr set to 0700 and the other one to 0701. And this is what it is needed.
Check you device map, the entries under aws3274 to check the device numbers,
The procedure for stopping is ok, I do it like you and then close the x3270 terminals I have opened.
SystemAdmin