ZS600KL Serial Number changed to C4ATAS000000

[brsteej]

Please tell us some basic information before asking for help:
Model Name: ROG Phone zs600kl
Firmware Version: 16.0420.1912.16
Rooted or not: NO / Locked bootloader
Hello
My Serial number has changed to C4ATAS000000 
So now i cant upate OTA
I cant unlock bootloader

any advice ?