Thank you for your request.
Normally, the ticket remains valid until the final station. With a confirmation from the ticket inspector, you can continue your journey. However, I recommend you to contact the issuer of your ticket.
If you bought your ticket via sbb.ch, you can call the Contact Centre on 0848 44 66 88 (0.08/min). You can also get more information at sbb.ch/help.
Have a nice day. Greetings ZoeS