Oneplus Two Imei Lost

Hello Folks,

As I am new to this forum so I dont Know whether I am creating the thread at proper place or not.

I am using OnePlus 2 Model No: One A2003. I was using Oxygen OS 3.1.0 everything was working fine. Then Hydrogen OS V2.5 came with the modem update which spports VOLTE. So I flashed this H2OS it booted up fine and then I decided to revert back to Oxygen Os, so I flashed it and I lost my IMEI Numbers. I recovered one IMEI from my efs backup but still the second one is missing.

Any Help Would Be Appreciated.