My main light failed on the trip to Italy when the car was only one year old. It was caused by the light switch. The fuses were still ok. On the 2014 4/4 the light switch is from an older Freelander or Discovery model, I don't remember exactly. The switch was replaced in southern Germany during the trip.
I noticed afterwards that with heavy rain there was always a drop of water continuously dripping exactly onto the light switch. Maybe that was the reason. I have fixed that since then.
As far as I know there is no relay for the main light, so in your case the switch may have caused an intermittent short circuit?
