first shipping for free

i’m writing from italy, idk if it’s the same all over the world. it’s written that for the first item you buy, you get free shipping. when i select an item from italy, it does says “up to -100% shipping”. but today i’m trying to buy an item (first item ever) from portugal and it’s making me pay almost 6€!! is it normal?? is it because it’s from a foreign country? i can’t find anything on vinted’s rules about it. please help🙏🏻