Cordova Device plugin: device.serial value does not match the phone's serial number

the device.serial value returns an incorrect value. The phone devices serial number starts with RF but the device.serial value is starting with numbers. I am able to get the model and android version, so i can rule out the option of plugin is not working.

Tested using Samsung Note 5, android version:6.0.1

device.serial value gives a 15 digit number while my serial number is only 11 alphanumeric character.
I have also checked the value against the IMEI number but it is not a match.