Redmine

I have 2 issues.

I set Issue 002 follows Issue 001. Issue 001's end date is Sept 1st.

If I change the end date of Issue 001 to 5 days later (to Sept 6th), I see Issue 002's start and end date aslo move forward (later) 5 days, which is good.

Here is the problem: if I move the end date of Issue 001 to 5 days earlier (to August 25th), the Start date and end date of Issue 002 does not move accordingly, instead, they just stay where they were - no changes. Why is that? How to fix it?

Thanks!