Hello,
You're in one page checkout.
I suspect that the payment form is displayed when the billing address is not yet available.
Since the Stripe JavaScript is not refreshed if you change the billing address ; when you got the Stripe payment form, it's possible that it contains no address details.
I do think that having 2 steps should avoid the issue ; but modifying the plugin in order to perform a refresh of the Stripe payment form if you change the billing address, it might have some unwanted side effects.
But it might be a solution to update the Stripe Customer object via API just before trying to confirm the Payment Intent.
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.