Lenovo z90a40 zoom Bug with torch light

Bug description: built-in torch app and photo flash use only 1 LED of 3. Lenovo z90a40 has 3 LEDs but 2 are not in use
Affected version: MK71.2-zoom-181020-RELEASE
Steps to replicate: turn on torch light or make a photo with flash light

It’s not a bug !
Even in stock rom, only one LED is turned on in torch mode.