R12 AP Invoice applying all active taxes at invoice line instead of applying the selected the tax cl

R12 AP Invoice applying all active taxes at invoice line instead of applying the selected the tax classification code.

We have 16 active taxes and the corresponding tax rates in our newly created operating unit and after completing the tax configurations we tried testing an invoice and provided an tax classification code at invoice line level and could see it is pulling all the 16 taxes irrespective of the tax classification code provided.

Please provide your valuable suggestions on this.

Thanks!