Re-booking a arrears contract to change payment

When we rebook a contract with an arrears payment schedule I am seeing that the adjusted amount is billed on the rebook date instead of the scheduled date. For Example if we have the below schedule

6	10,150.00	2-Jul-15
1	474,150.00	2-Jan-16

If I rebook the contract on 27th Oct and adjust 2nd Oct payment to 20150 as below

Periods	Amount	start date
3	10,150.00	2-Jul-15
1	20,150.00	2-Oct-12
2	10,150.00	2-Nov-15
1	474,150.00	2-Jan-16

  System is create a new AR invoice due on 27th Oct instead of 2nd Nov. is this expected system behavior. We want the updates to schedule to bill on scheduled date.

Regards

Geeta