What are partial rollups in your plan?

If your schedule bars have a striped pattern that fades out in one direction, this indicates that a parent work item is using one set date and one date rolled-up from child work items. This is called a partial roll-up, and is demonstrated below:

If a parent work item’s schedule bar fades out completely, it means that one date can’t be inferred since a child work item doesn't have a start and end date assigned to them. Missing start or end dates prevent your plan from determining a roll-up date, and so the schedule bar fades out.

To fix a partial roll-up, ensure that all child work items have start and end dates.