Dependencies breaking if New Task is entered

I've been noticing that our arrows (dependencies) have been breaking if a New Task is added in the middle of a project phase. 

We create our projects off a template. Any given project may have six to nine different phases. Individual tasks are added to the phases on an as-need basis as subtasks/sub-subtasks. From that added phases through the end of the project, the arrow becomes broken & even if the dates are set for that task, the rest of the project dates don't move along to accommodate the newly added date & the rest of the scheduled phases. 

It doesn't make sense to me as to why the remaining dependencies would break with the addition of a new task. It also defeats the whole purpose of us using Timelines since the dates are constantly wrong, but we can't not add the new tasks. 

The screenshot shows our template...

We need a solution! 😩

Julia Marantidi Home Automation Executive Account Manager & System Engineer