I am experiencing an issue while trying to subscribe to the Hobby Plan. My payment was declined with the error message: "Your card was declined for an unknown reason. Contact your card issuer for more information."

However, I have verified that my card (VISA from Nam Á Bank) is functional and is able to process international payments. I have also ensured that all card details were correctly entered. Could you please help me understand why this is happening and assist me in resolving the issue?