This is by design and is not a bad thing, its Workamajig's scheduling features updating your tasks based on what has actually been done by those assigned to each task.
Plan Start vs. Actual Start
- If no one enters time via the My Task Widget or Calendar screen on the Plan Start Date, then no Actual Start Date get populated and then the Plan Start Date will push out to the next day at midnight.
Plan Complete vs. Actual Complete
- If no one (all users assigned to the one task) checks the task as Done from the My Task Widget or Calendar screen, then no actual Complete date is populated and the Plan Complete Date will push out to the next day at midnight.
Predecessors vs. Completed Predecessors
- Tasks are linked in the schedule using the Predecessor option. This feature will push or pull the task next in line based on the plan/actual dates of the previous task. When a task is 100% done, then is become a completed predecessor and you can then run filters on this option to see just the next task only from the My Task widget, Calendar, and Traffic screens.
From more info on these features, please refer to the following guides: