G903m cert read / write error

Hi i tried read and write cert on g903m but not work

When try read cert, get done but cert are unusable file whit garbage data:

Code:

;Z3X Samsung CERT file
;Please do not edit this file
[cert]
Model=SM-G903M
SerNo=RF8G91X4HFV
IMEI=??i???u??|??L?
ImeiSign=7557FF9B7A8E454F739B4CA8571CCCA7..
PubKey=7557FF9B7A8E454F739B4CA8571CCCA71E...
PubKeySign=7557FF9B7A8E...


When try write cert get succes but imei not change and can select any cert file whit any ID but nothing works.

Im tried reset efs but get nv error, restore nv and get original imei but after write cert but imei not change.

Please fix thanks.