Account blocked - Credit Card Invalid

Hello!

My Amazon Selling Account suddenly shows the following message “Amazon is not able to charge with the listed charge methods. This could be either due to incorrect details or lack of bank’s permission for respective marketplace.”

I have not changed my credit card details ever since I created the account and there has never been a problem with the payment method.
The information given is correct (still the same, haven’t changed anything), correct (billing) address, credit card valid (until 2024), enough credit available, no limitations on charges, etc.

I opened a case and Selling Support just wants me to change the card without stating what is wrong. The problem is, I only have this one credit card.

Can anyone help please?

Thank you.