It's important to note that while Switzerland uses proportional representation (PR) for the lower house, there is a high level of disproportionality due to factors like varying constituency sizes and list alliances. This leads to disparities when translating vote shares into seats

At the cantonal level, where seats are distributed, the results were correctly recorded, but the calculations needed to obtain a nationwide result, which has no bearing on the distribution of seats, were off due to inflated valid ballot totals in three cantons, thus skewing the nationwide figures.