This could get complicated and confused, so let's clarify some of the terminology involved before going any further. [1] The charger is always, without exception, within the car. It is the inverter that transforms 230 volt AC to 400 volts DC (or 800 volts in some new cars) plus associated electronics for control purposes. [2] The equipment you plug into the car is called in the industry an EVSE or a charge point. It is either [a] a slow charge 230 volt AC electrical power supply plus electronics to communicate with the car, or [b] a fast charge 400 volts DC electrical supply that bypasses the car's charger and goes straight to the battery, plus electronics to communicate with the car. See what I mean about complicated?
Having got that out of the way, the fact you can charge at home on 230 volts AC means the car's charger is working. My questions then are whether the motorway charge point was a slow (230 volt AC) one or a fast (400 volt DC) one, and whether you were using your own charging cable or one fixed (tethered it's called in the industry) to the charge point? Answers to those questions may help us point to the fault.