Ez command plus and Dcc on Lionel ho polar express.

[Mandaranog]

I just upgraded my son to Dcc, he had a polar express set from Lionel. I tried to program the engine on a separate track. It takes the program but will not move, some sounds work some don't. Not sure what I am doing wrong. The other Dcc engine has no sound but programmed properly. All turns and turntable work properly. Any advise?
Thanks.