Hello Rusezi86
It seems to me that you are looking for international tickets. You have to provide certain details in order for the booking system to be able to correctly calculate the fares. The system has at least to know your age and if you hold any type of reduction.
You do not say anything about the platform you are using (sbb.ch or SBB Mobile app); furthermore, we can better follow your statement if you give us a real example.
Kind regards,
Roland