I realise that this thread is a bit old and that you said you were going to live with the problem.
I was beginning to think that my D5500 had a sensor which could detect fungus because my overexposures tended to be when I was taking live view shots of mushrooms. Anyway, I went away for a few days during which time I was at my sister's house and had my camera sat next to me on her leather sofa. Somehow, it slipped off and hit her hardwood floor - fortunately lens hood first. The lens hood needed replacing but the camera and lens seemed to be undamaged; though I am now paranoid about every slight looseness of the lens.
Since I got back, I haven't really taken any mushroom shots with or without live view but today I did and whilst they would not win any awards and the lighting was a struggle, the exposure is significantly better than it was.
I wouldn't like to claim that the knock made the difference as I have also made a number of changes to the settings (not all to my liking) having watched some tutorial videos. Or maybe it was just due to the poor lighting; who knows...
