When you try to book a ticket from Italy to Zurich for April you get this very confusing error message:
Unfortunately, there are no longer any tickets available for the connection you have selected. However, during this booking process, our partner railway has provided some alternative connections, for which you can still purchase tickets.
That all tickets for direct trains between Italy and Switzerland have already sold out 4 months in advance is most certainly not the case. So what is really going on here is that the seat inventory for those trains has not been loaded yet. And thus reservations cannot be made, and as a result purchases for those trains are not possible.
So basically we are to early to book these trains. However telling people that they are already to late is confusing. Not helpful. This is an error in the booking system that has been rather persistent. When will SBB finally fix this?
The error message should namely read something like “currently purchase is not yet possible, come back later”. Ideally with a date from which purchase will be possible, as many other railways manage to do.