Difference in Expense Report Tax in Payables rates

It has been observed that tax rates defined are different from what are computed at AP Invoices. For example, we defined a tax rate SM, with rate 18.06% (18.06/100) or (0.1806), however when the expense report is imported into the system. It is observed that the system computes the rate as (18.06/100+18.06), thus making the tax value lesser than expected.

This enquiry is to know if this is the expected outcome?

In addition, the tax is expected to be credited to the tax liability account, instead it is observed to be crediting the payment liability account in such a way that it is assumed that the tax is payable to the vendor. Is there a setup that can ensure that the tax rate account defined is used?