Transfer Order error Correct quantity specification (total of three quantities = &)

Hi,

I am trying to create and confirm a TO from an external system. The external system sends the data (TO number and SU number) and the TO gets created in SAP. We have created an enhancement for Basic IDOC type WMTCID03 using exit EXIT_SAPLLIDI_002.

Now, when a TO has same material in say 2 deliveries the TO gets confirmed. However, the same doesn't happen when the same Material is split in more than 2 deliveries.

For e.g:

Material: 18000 - 1 CAS - Delivery1

              18000 - 2 CAS - Delivery2

              18000 - 3 CAS - Delivery3

Total number of units to be picked = 6 CAS.

^^ In this scenario TO doesn't get confirmed and throws error Correct quantity specification (total of three quantities = 0)

However, in case as shown below:

Material: 18000 - 1 CAS - Delivery1

              18000 - 2 CAS - Delivery2

Total number of units to be picked = 3 CAS.

The TO gets confirmed without any error.

I want to know if I am missing any parameter that might trigger that error. Any help will be appreciated.

Thanks and regards,

Rishav