When the cart billing address is empty, the cart states cart.billing_address must be an empty object {}.
Shipping charge is not shown when "Free shipping" is selected.
Show the "Other Addresses" section if the cart address is a "new" address and the customer possesses addresses in the book.
Guest checkout scenario & billing ≠ shipping: When we save billing address, it will make billing = shipping in the UI perspective. However, in the background, it saves billing address only and the shipping address remains intact.
Translations seems to be missing for the below strings
cart.billing_address
must be an empty object{}
.