Isn't the second one a plug and play accessory track piece?

That’s what I assumed when I bought the accessory. But the accessory requires a 3 wire connection and both on my tracks are barrel connectors. So I can not plug the accessory in.

Is the accessory specifically a plug n' play one? I think it has to be in order to work for that track piece--unless there is an adapter. Check the part number. Is it this?

LIONEL #6-81063 PLUG N PLAY AUTO GATEMAN 

Most new LionChief starter sets produced in the last couple of years generally come with one terminal section and one plug 'n play section.

What set do you have; how long have you owned it; and did you buy it new in a sealed box ?

Perhaps it was a packaging error where two terminal sections were included instead of one of each, but I assume you would have noticed that when you put the set together ?

Must be a packing error. I have the LionChief Blue Comet set. Bought it new, sealed in the box from Amazon.