Unlike in other countries, in Switzerland, tickets do not come with seat assignments as regular tickets are valid for any train during ticket validity. Furthermore, seat reservations are only possible for IC, EC, RJX, and TGV trains.
If you want to make seat reservations, please try to call: +41 51 225 78 00. If it does not work, you can still do seat reservations when you arrived in our country; any staffed railway counter can do it.
Tickets in the SBB Mobile App are displayed provided you have bought them using a customer account (logged in during purchase) and you are logged in with the same account while using the SBB Mobile App.