I have two RPi 3 B+. One of them has camera connector with black latch/black slot, the other with black latch/white slot.
It seems to me that the board with white slot is incorrectly mounted. Camera connector is flipped by 180 degrees.
RPI with cable latch turned to ETH works OK with camera (black latch and slot).
RPI with black latch/white slot has cable latch turned to HDMI connector - this is different than in all previous RPi versions.
With camera mounted - it won't even start. Component on camera board soon become very hot.
Can You confirm this assembly fault (reverse mounting of camera connector)?