Incorrect Exchange Rate amount posted when changing the currency rate in AP Invoice

Hi,

I'm using SAP B1 version 9, PL7.

I have encountered error in the incorrect Exchange Rate amount when  posting in the AP Invoice.

Below are the replication steps.

1. Create PO (BP currency = USD), local currency = SGD

2. Create GRPO rate is 1.2551
    DR Inventory  USD  7104.00                      SGD 8916.23

    CR  Allocation Account    USD 7,104.00                              SGD 8916.23

3. Crate AP Invoice (copy from GRPO), change currency rate to 1.252240. The system generated GL entries below:

    DR Allocation Account              USD 7,120.23    SGD 8, 916.23

          Inventory                            USD      -8.11    SGD    - 10.16           
          Exchange Rate Gain/Loss  USD      -8.11    SGD    - 10.16             
          GST                                      USD    497.28    SGD      622.71
  

          CR Customer - Debtor Account            USD 7,601.28            SGD 9,518.62

      Automatic JE is also created after posting the AP Invoice above: (I think this entry is correct). The Allocation Account was closed.
        DR Conversion Gain/ Loss      SGD 0.00    USD  16.23
        CR      Allocation Account        SGD 0.00    USD  16.23

In the AP Invoice GL entries above, shouldn't the system do below  entries for Inventory GL account and Exchange Rate GL account?
          DR Inventory                      USD -16.23        SGD      -20.32
                Exchange                      USD -16.23        SGD      -20.32