If you choose credit card as a payment method when ordering, it can happen that the payment is rejected. Payments linked to a credit card are checked for fraud sensitivity. We do not naturally assume that you commit fraud, but checks are carried out for this. The details of this process cannot be shared, and neither can the reason for rejection. The above can also occur with a PayPal payment.
If a payment is rejected and you still want to order, we would recommend trying another browser / incognito tab or choose another available payment method.