Hello Chris25
Welcome to the SBB Community.
We are a customer support forum run by volunteering travel experts, we are not the SBB Customer Service. A hi is always appreciated.
Have you checked your account on sbb.ch? Does the ticket appear there?
Have you got a purchase confirmation e-mail for all the tickets you have purchased?
If the answer is no, you simply purchased a one way ticket.
What is the trip for which you had purchased tickets?
Important is, you have to check once again before entering a public transit service that you are in the possession of a valid ticket. This no matter if you had purchased the ticket yourself or at the travel center. Mistakes can happen.
In addition, why would you have been fined provided you had a valid ticket? In this case you could have brought a proof of purchase. You would have paid CHF 30.
Finally is it the SBB Mobile app or the SBB Preview app?
To me, it sounds more like an user error. If there was a general issue, this would pop-up immediately and many passengers would report the same issue, yet there is none.
For further investigations we would be in need of more information.
Kind regards,
Roland