Billing address autocomplete prevents adding a payment method

While attempting to add a billing address for a payment method at

https://account.apple.com/account/manage/section/payment, I'm experiencing an unusual problem.

It won't allow me to enter my billing address properly. It will attempt to autocomplete to a city sharing my street name. For example, typing "456 South St" (a test address) will show cities sharing that name. It doesn't allow my actual address as an option, and instead forces me to choose one of the cities. Even when I try to subvert the autocomplete, by entering the address directly and then clicking Submit, it will fail with "unable to add payment method".

I've tried turning off my password manager (NordPass) and still had the same problem. I've tried this in both Safari and Chrome.