It sounds like there might be some confusion for some on this topic. Mainly with what USB ports are on the center console on some models.
Some trucks two USB ports in the center console. The one USB port ties into the UConnect for streaming music from a flash drive or mobile device (iPhone, iPod, Android device, etc.) and is the port that likely will also charge your device at .5 amps. The other port (sounds like maybe optional?) is a dedicated 12v USB charging port that is supposed to charge at 2.1. See pic below (sorry owners manual pic, not from actual truck).
We've got a '14 Ram 2500 CC with the configuration I mentioned above and are having this very same issue where we have to unplug and plug back in the charging cable for our iPhone's. So far we haven't checked to see if it's the same issue with other mobile devices, presumably it would be no different.