The mobile app does this fairly frequently, as it tends to mix up dates for boarding passes. My last trip to SMF was 2/2 - 2/3, but the mobile boarding passes had my segments 2/1, 2/2, 2/2, 2/3. Refreshing just scrambles them up again. There doesn't seem to be much rhyme or reason for how they're sorted. Guessing it's a related issue.

Might be worth just printing passes from now on, especially with mileage crediting issues popping up here and there on the forum.