The Little Benefits of Manually Scheduled Tasks

Manually scheduled tasks can have dependencies. When you set dependencies, Project will adjust the manually scheduled successor task only for the first time.

This results in little benefits:
a. When manually scheduled task violates a dependency, you will notice a red wavy underlines in Finish date.

b. When the driving task finishes early, the manually scheduled successor will not reschedule to earlier date and you will notice a green wavy underline in Finish date.

To fix this problem temporarily, you need to select the current task and click Respect Links command in the Schedule group in Task ribbon. This action should be repeated every time you get the warning

Permanent solution is switch tasks to auto scheduled. Select all the tasks and click Auto Schedule in Task Ribbon