After importing Journal Transactions in which a specific subaccount is listed...
... when checking those transactions in Acumatica, the specified subaccounts are not shown:
In Acumatica's Chart of Accounts, the box for Use Default Subaccount (for the accounts in question) is checked:
Because of this setting, Acumatica automatically overrides the subaccount data coming from Velixo with the Default Subaccount specified in Acumatica's General Ledger Preferences:
The Use Default Subaccount setting in the Acumatica's Chart of Accounts would need to be UN-checked...
... for any account for which a non-default subaccount would need to be uploaded from Velixo: