In ScreenSteps you manually control the order of your articles. When ScreenSteps updates Zendesk it will set the position of each Zendesk article based on its position in ScreenSteps.
But Zendesk lets you use several settings for ordering articles besides the article position. You can have articles sort chronologically, alphabetically or by popularity. If your Zendesk articles aren't showing up in the order that you expected then check the sort settings for your section or forum in Zendesk.
Other things that affect sort order
If you have articles in Zendesk that do not exist in ScreenSteps then you may see problems with ordering articles. ScreenSteps updates the position of articles based on the articles that are in ScreenSteps. If there are articles in Zendesk that do not exist in ScreenSteps then these articles will not be accounted for when updating article positions.