Hello,
Check you CIF integration model it should have stock and batch should be selected in same IM.
If high number of stock postings in a very short period of time is done the flag reread stock must be set in ECC system in transaction CFC9.
Refer SAP Note 492591 on Stock FAQ helps and KBA
1889338 - CIF does not transfer always the correct stock quantity to the connected SCM system
Best Regards,
R.Brahmankar