A couple of times I've noticed that the part of the windscreen on my Model Y that covers the cameras hasn't defrosted in the same way as the rest of the windscreen. Is this normal, or do I have some sort of fault around the camera housing? With the very cold overnight temperatures this week it's been quite noticeable, and I took this photo yesterday showing the windscreen fully defrosted in about 10 minutes of turning on the climate control, but the glass over the camera still having ice on it.