Hi,

Please share admin access. We will try to inspect problem on your site.

I see this on cart page in your site:

This is woocommerce interface and I don't correctly know how it works. I need ftp access to test and inspect that.

Can't connect  with this data. Please check it.

Please correctly configurate ftp user. I see only empty directory. I suppose you need change ftp user available directory,

I suppose problem is in configuration of Mercado Pago plugin. It doesn't return corrent info for woocommerce plugin. I see that next code for mercado shipping metods

$shipping_method->get_rates_for_package( $package )

returns empty array.

Try to contact Mercado Pago plugin support.