This can happen if the Maximum Units value for the task is set to a number smaller than the resource capacity. To check and/or update the task's Maximum Units, click the task in the Gantt chart and locate the Max. Unit value in the Task Details Popup.
![](/documentation/gantt/files/latest/data-center-and-server/46336618/57941703/1/1542209696000/Max+Units+-+Edit.png)
This Max. Units value defines the maximum number of resource units that can be allocated for the task.