Shipping is lost updating confirmed cart

I use stepped checkout (login, addr, shipping, payment, cart/confirm). I have a manual payment to catch cases of product for free shipping. All other products are chosen by the customer.

On the cart/confirmation screen, if I add/remove an item or delete it, the cart removes ALL shipping. The customer could then checkout without shipping charges.

If I click on payment (path), HikaShop takes me back to the shipping step (correct) to verify my shipping options after the cart change.

See attached. Need help with this.

That will happen when the fact that you changed the products in the cart changed the shipping choices and that the auto select shipping and payment methods option of the configuration is turned off.

Did you try to finish the checkout at that point ?
The system would automatically redirect you to the shipping step for you to configure the shipping.