Hi,
Thanks for the report.
The inline address edition in the checkout has been mostly design to be locally submitted.
In the screenshot "address_selection" you can see a validation tick which allow to submit the address.
Afterwards we added the support of the addresses submission when clicking on "next" but if one address is validated and the other not, the checkout does not re-open the address in error in the checkout page and just use one valid address.
We are currently working on a refactoring of the checkout system and I added that issue in the points to fix with the new structure.
Right now with the actual code it will require some modifications in the core and in the views. So the checkout could know which addresses was in edition and which address haven't been saved (so the modification in the core in order to provide that information).
It is not very easy and regarding the current development for the checkout (what I'm doing since we finished the new backend product edition), I think that it's better to be sure that it will supported in the new checkout system.
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.