I have the same issue,
I toredown a second time the device and check visually the rear camera and saw no damage.
I use the opportunity of this post to ask to Max if you saw a damage to your rear camera ?
You change your rear cam to solve your pb ?
There is any way to check the rear camera alone to check if it works prior to put back on the motherboard ?
Thank in advance for your time !
Cheers,