If admin role id don't have edit task workflow then admin won't be able to change the sequence of the task as shown below.
Successfactors Learning (LMS)
Learning Management System
Please add below workflow to give admin access to change the sequence of the item.
-- > Edit item tasks
After adding "Edit item tasks" workflow admin can able to change the sequence as shown below.
Tasks, item , edit task sequence , LMS , KBA , LOD-SF-LMS , Learning Management System , LOD-SF-LMS-COR , LMS Core - Items, Catalog, Curricula , Problem