Hi,
I don't know how that's possible.
Did you customize hikaShop views ?
Are you using the new checkout or the legacy one ?
What is the URL of your website ?
Are you able to reproduce an order like that ?
Are these orders from new users ? With new addresses ?
Or maybe these addresses / users date back from before you made these fields required ?
Because once an address is created, it can be used for an order without the system checking that all the address fields abid by the restrictions in them. So that could be an explanation.