Updated PO schedule line didn't transfer to APO

Hi All

i got a problem，when i update the schedule line of Purchase order，it didn't trigger the CIF process。so the schedule line data were still old one in APO。my operation is below:

1. tcode: me22n to change a PO

2. insert a new schedule line，line number is 2

3. then delete the schedule line 1。

usually，if i just insert a new line or delete a schedule line， it will trigger the synchronization，and the data in APO will be updated。But, when I combine both operation，nothing happen。line 1 is still in APO，line 2 is not exist。

Even I run the CFM1，CFM2 and RIMODINI，it only update the line 2 to APO，but line 1 is still exist。So I have to run the CCR all the time，or it will make a wrong forecast。 doesn't anyone know what happen and how to figure it out ?  thanks !!