Write cert sm-g920p failure?!?!

I had the latest firmware running on the SM-G920P (G920PVPU3BOL1_G920PSPT3BOL1_BST) and the logs indicated that the CERTIFICATE WRITE was SUCCESSFUL, although when I checked the IMEI of the phone it remained the same. So, after researching, I came to the conclusion that downgrading the firmware may help the issue.

I downgraded the firmware to G920PVPU3BOI1_G920PSPT3BOI1_SPR and once again, the logs indicated that the certificate was written successfully….yet once again no luck! Please help, anyone. I looked through the threads on the forum and there is NO information regarding this issue.