Custom address fields checkout not saved in session

In checkout you have your address (billing and delivery), standard behavior is that data from your account is loaded. This is working fine. But we have added some extra fields like separate field for house-number and addition. Those are also loaded initially correct.

But when user wants to change address of delivery for this order to another address the data is saved to session. The default Woocommerce fields are saved correctly but the new added fields aren’t. Which results in an incorrect display of address information. This will occurs when user is navigating away from checkout after editing address info, to do something else and then go back to the checkout. Then the address info is mixed up with data from account and session.

I added the additional fields to my checkout with the standard Woocommerce filter “woocommerce_checkout_fields”.

With best regards,
René

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