Tax calculation issue

All additional fees do not include tax on the cart or checkout. Even when WooCommerce is configured so prices are inclusive of tax. The issue seems to arise from inc/prices.php line 1273. This is an if statement with the following comment “if wc prices include tax: substract the tax from additional fixed fee since already WC will add tax.”. I do not understand the logic here. Why would WooCommerce add tax to prices that already include tax?