We can’t figure out which bus you’re referring to. SBB is not operating buses; therefore, we cannot help you.
I kindly ask you to contact the bus company to understand why the bus was not departing as per schedule. I assume that the bus was either late or the schedule is not up-to-date. In the latter case, the bus company would have to send an updated timetable to SBB to fix the wrong information given by the SBB Mobile app.
The information on the bus operator as well as contact details is available on the timetable board, usually in the lower left or right corner.