Hi,
I see that you have variants (Caratteristiche) and theses variant override some default product options, like the weight.
You have to edit your variants and specify the weight for each of them.
We already know that, sometimes, your variants have the same weight and the fix is already in our TODO list for the next release.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.