Fixed Effort tasks with the default 0 h effort were incorrectly turning into milestones when a resource was assigned, causing their entered duration (e.g., 5 days) to collapse to zero. This behavior was incorrect.

When a Fixed Effort task already has a duration, the effort should be derived from that duration (Duration × Units ÷ 100) rather than collapsing the task to a milestone.

Tasks no longer collapse into milestones when a resource is assigned while the effort remains unchanged.