Intercompany FOS Credit Memos wrongly calculated in Oracle

We have a specific case with intercompany FOS invoices, for which Intercompany credit memos get wrong calculation of total value.

Based on the analysis done, this is the scenario that is leading to the situation:

Forward flow order is shipped with different tracking number for the same item, due to multiple boxes used (each box gets a different tracking number, shipment happens at them same time for full order). Due to the different tracking numbers, this behaves like a split shipment in Oracle.

Return in full gets created, after initiation from customer, without using any tracking numbers, therefore this is one single shipment.