Edit: Thanks, as it was pointed out in the comments, it is indeed possible to set a permanent billing address.
Check if your data is shown on https://itch.io/user/settings/billing-address
It is persistent. If it is not, then there might be some problem with your account. Your account is old, maybe there are some faulty data entries that are now incompatible or whatever esoteric computer reason. And an US site will not care about privacy or any other local law of the user. There is something about this in the tos, which laws are applicable. They might however care for certain trade agreements, since there will be money flows.