Waiting for author
Reported for: WooCommerce Multilingual & Multicurrency 5.3.2
Overview of the issue
If you set the price for custom fields using the Advanced Product Fields Pro for WooCommerce plugin, you will notice that prices won't be updated when the currency is switched.
Workaround
At the moment we don't have a workaround available. However, the author is aware of it and he is working on its implementation.