Default [Q] L-07c network lock need your help!

Dear all,
I have a L-07c with 10d rom then i try to use the 20b, it's ok but when i return it back to 10d, i check in Erase entire CP my L-07c was network lock, i put the correct imei into my l-07c but nothing change it still network lock. I need some suggestion, please give me some.
Best Regard.

P/s: sorry about my English