ZE550KL Bootloader Problem

Need Help..

I Am trying to Unlock my Bootloader in my ZE550KL:

- I was on Marshmellow stock Rom.
- Flashed 1.17 but was not able to unlock my bootloader.
- Then Flashed to 1.16.40.763 But still unable to lock my bootloader.

I am running Asus official Bootloader unlock tool(Unlock Device Tool) it is running without any issues but when i check the phone status in fastboot mode.

fastboot oem device-info

But bootloader status is false..

Please can someone help me how to unlock my bootloader..