Hi
I've had this issue and just had it sorted today.
The issue is with the module which sits on the back of the whole headlight unit. It burnt out. Which means very little light is getting through to the reflector (the bit you see looking at it)
I told the dealer what the issue was as it happened on my MK8 fiesta... twice!!
I've posted photos below from when my fiesta did it... just so you know the issue.
My local dealer just replaced both headlights. If one side does, the other side will no doubt go very soon also.
In one photo you see the burnt LED'S in the other photo you see the damaged/melted but on tip of reflector
