Resolved
Reported for: WooCommerce Multilingual & Multicurrency 4.10.3
Resolved in: WCML 5.1.0
Overview of the issue
If you are using the WooCommerce Multilingual multicurrency feature and a custom gateway setting for secondary currencies is set as BACS or PayPal, taxes are not being applied during the checkout.
Workaround
Our developers are working on it.