Not weird at all... They will locate you by your IP for multiple reasons:-

1. Pricing offset based on region
2. this is just my suspicion, no proof at all... financially, they are managed by different agents for different region and different agents will only accept certain country for banking.

This also happens on Steam, Google Wallet, Microsoft, Paypal (e.g you cannot use Malaysian card on US account) and many more that I don't know about.