(N920T) IMEI function on z3x not working

Recently I bought an Z3X Box through eBay but when I try to change/repair the imei of my Note 5 (SM-N920T) it says "Repair Done" but when I check my Notes IMEI, it says it as all 0s. 000000000000000.

Please help me resolve this!

I tried 2 different firmware, and 2 different N920T, same result.
Tried patching the certificate, and the problem still remains.
Can get the original IMEI back if I write the auto back up.

Thank you guys! :confused::confused::confused: