Your tasks can be sorted many different ways.

From your task view, tap the menu bars at the bottom right and choose sort to show the sort order options.  

On this page, drag/drop the sort options to the top of the page as you want them to be applied.  (You will need to use the 12 dot square on the right of the option to drag and drop)

For example if you want to sort your task on title a-z then you would drag that option to the top of the list.  If you want to reverse the order, like sort tasks on title z-a, just tap the sort option and it will reverse.