I have a question re the Disneyland Train Set that we bought for our 6 year old . ( in a blue box, the four characters, the bell that turns on train sounds and the smoke that comes from the stack.) . The engine car connects to the "coal" car ( it has (6) - C batteries.) via a plug between the cars . When I plug it in it's fully functional ( not tight though) , and after 1-2 times around the track it comes unplugged and therefore stops. Upon closer inspection , it appears that the "plug" is about halfway in and possible should be farther ? ( I'm trying not to force it/damage it) ...or is it designed this way like some sort of kill switch? *** Would love to hear some thoughts or insight before having to exchange it.