Not Exactly A Bug --- Perhaps A Twitch (nec Session F03-2 To F03-3)

This happened yesterday (5/7/2018) while I was running a couple of the NEC freight sessions. I had completed F03-2, which involves taking a load of trash cars back to the yard and dropping them at the designated destination.
Rather than wait 10 minutes for the next service to start, I dropped back to the main menu and selected it: F03-3, stabling the engine, which opened with the engine again coupled to the trash cars. Odd, I thought, but got out of the cab, uncoupled them again, re-entered the cab, set up the controls, checked and set switches to the next destination, and started moving. When I checked the 2D map again, the destination marker had disappeared!
After a bit of head scratching, I shut down TSW completely, restarted it, worked my way back to F03-3 and launched it again. This time, the cars remained uncoupled, the destination remained in place, and I completed the service normally.

This is the first time I have encountered a problem with the NEC freight sessions, which I also appreciate because they come in small bites.