When I am viewing a smart list (usually the Today view) on the watch, the tasks are continually shifting position, making it almost impossible to tap on one and then complete it. I pretty much always end up tapping the wrong task because the order changed.
I have changed the list I am viewing multiple times. The shifting exists on all the smart lists for the watch, but not regular lists.
I do not know if this is because all the tasks that are shifting around have no due time, only a due date. However, when I tested my "tomorrow" smart list I can see two tasks with the same due date and time, and they swap back and forth. There are also a bunch of tasks without due times, and they swap around as well. But the tasks with times and the tasks without times do not swap with each other.