By default, the conflict auto-resolution is disabled, in chart configuration. Meaning, should be there a conflict between the duration and work for a given task, you will be prompted to resolve it manually by using one of the options below:
use work value to define the task duration (the most common choice)
use duration value to define the task work
set fixed duration (task duration that is independent from task work)*
Please note that all conflicts will be resolved in Gantt chart but only selected changes will be saved in Jira.
Check the checkbox Auto resolve in the future to resolve the task conflicts automatically, in the future. As a result, the task work value will be used to define the task duration. You can always switch back to manual conflict resolution by disabling ‘Auto resolution of conflicts’ on ‘Extended settings' tab, in chart configuration.
*- when resizing a task with a fixed duration only the task duration is changed, the task work remains intact.