Terms & Conditions - no selection - goes to the first step

-- HikaShop version -- : 4.01
-- Joomla version -- : 3.9.1

Hi,
I have 4 purchase steps. First address + login, second- basket, third delivery and payment, fourth summary and Terms & Conditions. When the agreement is not selected, I click buy, it moves me to the first step. How to configure to display a warning. I do not want to go back to the previous version Hika.
Additional question: in the second step I have a basket, but I do not want to show the cost of transport - is it possible?

Hi Philip,
Here is a product that you can add to the cart and go through the purchase path:
tappi.klient-admin.studioprzylesie.pl/na...wozek-spacerowy-k2go

Attachment configuration

Can I count on some support?

Hello,
In the meantime, I found another mistake. What I wrote about applies to the entire purchase path. In the case of mandatory fields, it also does not work properly - no error message (no mandatory field filled in).
Here is a link to a working purchase path where "Checkout legacy = yes" is enabled:
tappi.klient-admin.studioprzylesie.pl/na...-puzle-animal-joueco

Here is a link to a non-functioning purchase path where the "Checkout legacy = no" option is disabled:
tomek.demo5.pl/nasza-oferta/produkt/382-...-puzle-animal-joueco

Please, solve the problem.

Hi Nicolas,
I checked the default Joomla template. It seemed to work. That's why I passed the problem to the template manufacturer. This one checked and it turned out that it was not the template's fault. The problem was Hika's configuration. The purchase process was set to force the start menu. It was enough to change to none. Works correctly. Thank you for your time and tips in finding a solution to the problem.