Boot handle reverse camera

[Peakie]

Hi, I’ve a Mercedes e220d (c238) 2018 and in the last few days when I select reverse the camera comes on for a split second then goes off, on the screen in the car a camera with a cross through it appears, the little flap which covers the reverse camera seems hard to move up where before I’ve been able to lift it up to clean it, any ideas what could be wrong.? Cheers.