Smart Sorting isn't sorting correctly — why is that?

Usually the order simply isn't fully learned yet: pon needs a few trips per store and only learns from your own check-offs (not those of other participants). So give it a few trips — it gets better each time.

Also check, in an open list via „⋯“ at the top right → „List settings“ → „Sorting“, that „Smart Sorting“ is selected there. You can pin any single position by pressing and holding and dragging it to its spot at any time.