ESS workflow

Dear experts!

I have an issue as below:

In V_T554S_WEB, i have configure all kind of leave will be used the same work flow:

My configuration: in Workflow Template:

I checked Process Request Using Workflow

and 3 WF ID for (new, cancellation & change), just only 1 workflow. In my case it's 90000099.

But my problem is: in my workflow: 1 rule for choosing approver. We just fixed 1 employee number.

For example employee B is a manager of employee A. ( relationship from A to B is A-002). But our request is: leave request of employee A will be sent to C. We already fixed it in rule of work flow 900000099.

The first time: A create Leave Request, work flow sent correctly to employee C. It's really good. But our problem is when A modifies ( he edit the length of leave or changing note). The request of A is moved to B. I am really shocked. Because we already fixed employee C in workflow to receive all request from other employees.

So every employee in system when creating all requests will be sent to C (correctly), but whenever changed or modified by creator, these request has not kept in Universal work list of C, they will be moved to their managers ( through relationship A-002 in positions).

Please help me!

Regards!

Woody.