When I am using the option of 1-2 zone extension to buy the ticket , the purchase ends up with the local ticket. ex I am in Zurich and selected to buy a 1-2 zone extension ticket, the ticket is showing up as zone 110 ticket. This has happened earlier too and have had to then get off the train and buy another ticket ..
In order to advise you on the best way, please send an e-mail to ticketsohp@sbb.ch with screenshots and the details of the problem that you had (stretch, time, date).