But before you upload, try to verify what I stated...
1) Delete the part.
2) Place a new one back on the breadboard in the same place.
3) Look in schematic view... Wiring for the part is gone.
4) Rewire the part in schematic view.
5) Look at breadboard view... I keep seeing the part has been moved off the breadboard and then connected with wires.
6) Delete the wires, move the trimmer back on the breadboard, and the ratnest line shows up again.