From your new video, please understand that these TnA trains have 6 different tracks each causing a different set of sounds/talking and action. Moving the train back and forth over the same track will not cause a different result. As mentioned before as well, holding the wheels or manually moving the train while it is in can cause the plastic gears to crack.
https://youtu.be/wIG5NC9CO5A
https://youtu.be/wIG5NC9CO5A