Anyone have any advice? Trying to utilize a CSV to create customer payments for a non-primary subsidiary. I.e. Customer has a primary subsidiary of A but also have B and C assigned to them. The CSV is to create a payment for an invoice assigned to subsidiary B, but we keep running into errors for any account where the primary subsidiary does not match the tx we are trying to create

Are you setting the value of the subsidiary in the import mapping? I know in the UI, that value will get set automatically when you select the account, but you might need to explicitly set it for imports.