It may be because your device is from a region where call recording feature is unavailable. (Samsung default call recording feature is only available in some countries including Sri Lanka so if your device is from a another country you will have to change CSC code in your device to a supported countries CSC code like SLK which is Sri Lanka's CSC code (but it is not recommended to change CSC code due to issues that might arise like warranty issues) so it will be better to use a third party call recorder instead.)
