Incorrect tax calculation in direct ship order AR Invoice

We created a sales order for an external customer in South Africa OU with the item being sourced from Ireland. When we shipped the item from Ireland it created an intercompany AR in Ireland and intercompany AP in South Africa. Also the customer AR got created in South Africa. However tax on customer AR in South Africa is calculating both the South Africa VAT and Ireland VAT. South Africa OU is subscribed to South Africa VAT as well as Ireland VAT so that the intercompany tax calculation is correct. Please let us know how to resolve the issue of dual