I have issue front camera missing, I've followed this step from reddit user u/taurnake
"I have the same issue my front camera button is missing. But, I resolve the problem by doing the following steps:
1. Switch off your phone
2. Press together the Volume Up + Power Button
3. Select the RESTART BOOTLOADER. Use the Volume button to navigate and press power button to select.
The front camera button of my phone appears again. Hope this one help your problem."
Then the front camera appeared, not sure for all camera issue, just another way that works for me.
