Make sure that the your package knows where to find the proper config file. It must be the exact same path in either environment like C:\configFilepath\configfile.dtsconfig. If the path is different in each environment, then it won't work unless you are using something like an environment variable as your base configuration pointer.

One other thing to be aware of, that took a couple of days from my life, is where exactly are you executing the package? If you are logged into SSMS with a remote connection to the production server and executing the package from the production environment by right clicking and executing the job, then the job will read the config from YOUR PC. If you want to check if it is reading the proper config it must be executed from the proper environment through a SQL Agent schedule or some other means where your personal PC is not part of the equation.

Good luck.