Hi Carlos,
Sorry for the late reply.
Ok, I’ve just sent you our newest development version 1.9.0 via email. There I’ve expanded our “Advanced: Manual Min Amount” settings, and moved them to a new separate section in “WooCommerce > Settings > Amount Left for Free Shipping > Manual Min Amount”. Now you can set different manual min amounts per shipping zone as well. Please give it a try and let me know if it’s working correctly.