SD_SALESDOCUMENT_CREATE Scheduling

Hey,
I have a problem with the Bapi SD_SALESDOCUMENT_CREATE.
In the table SALES_SCHEDULES_IN I pass on a schedule line:

REQ_DATE = 06.12.2021
REQ_QTY = 100

In the SCHEDULE_EX I now get two schedule lines back.
1. REQ_DATE = 06.12.2021
1. REQ_QTY = 100
1. CONFIR_QTY = 0

2. REQ_DATE = 30.12.2021
2. REQ_QTY = 100
2. CONFIR_QTY = 100

But, for 06.12. i have 50 PCS in stock. In VA01 the schedules a generatet correct (50 PCS for every schedule).

The COMPL_DLV Flag in the Header is not checked.

Any ideas?