Okay, it shouldn't have anything to do with your DCC system or wiring. Try a factory default reset of the decoder and start over. Sometimes weird values are left in some of the CVs during testing.
No, that is not normal at all, but indicates that perhaps your track voltage or amperage is too low. What DCC system are you using? How many track feeder wires do you have connected around the layout? What gauge of wire is your track bus? Much more detail is needed in order to determine where your problem lies.