I figured out what's wrong.

There are two molten copper/molten iron signal. One from "Intermediate product" and one from "fluid product".
This is extremely confusing


Yes, they absolutely need to change that, it's caused othees issues too (and while there at it, fix the 'copper wire' signal ...

Thank you for your reply

I figured out what's wrong.

There are two molten copper/molten iron signal. One from "Intermediate product" and one from "fluid product".
This is extremely confusing

What did you do?
I set circuit conditions to dispatch trains when there are not enough ingredients.
I send molten iron/copper signals to train to get it running but the signals don't fire the trigger.

What happened?
When the train runs, I checked my electrical pole on Vulcanus
I discovered ...