Lets enjoy a bit of quality time learning the heart of the Sim390 ESA/390 emulator. This should take the mystery out of what its trying to tell you.
So before we jump into MUSIC/SP we should know what stuff like the Program Status Word (PSW), wait state, ports, Task Control Blocks (TCB) are telling you. With this out of the way, you will have a much more enjoyable experience as you learn the basics of mainframe OS's via MUSIC/SP before we move on to Hercules and MVS.
* NOTE: I often say TCP, but think TCP/IP. Also, I suspect that the local 3270 sessions, even though they are initiated through Sim390, may actually be connected behind the scenes as TCP/IP TN3270 sessions. I don't have access to the Sim390 source code but I guess I could use a network tool to find out.
If you haven't done so already, you can download my MUSICSP-tk.zip file here:
https://drive.google.com/file/d/1-s8mobe5iWJFH6shyds44UM4t7IpwZSO/view?usp=sharing