Rear Camera Failure on BMW 2017

[BMW555]

Hi BMW SG colleagues, I am new to this forum and glad to meet with all of you. I need some guidance here. I am wondering if anyone have experience with having a problem with your BMW parking rear camera views as the camera sometimes turn black (which means I could only see any view from the display though the sounds parking signal works fine) but the some other time, the camera works perfectly well on my car. Thanks for the advice.

 

[BMW555]

btw, I sent the car to PML, they reinstall the software but the same issues still there....so it works well sometime but some other times it turns black (like the attached picture).