Why is my prepaid virtual Visa not working on eBay?

I got a prepaid virtual Visa card specifically for the purpose of making online purchases.

The instructions say to simply enter the card info like you would a debit card. I've successfully used it before on other sites, and from what I understand you are supposed to be able to use them on eBay as well, but when I've entered the payment info and click "confirm and buy," I am told "we are unable to process this payment" and told to check the card details or use a different payment method.

It doesn't work when I link the card to PayPal and try to use it through there either.

I have more than enough money on the card to make the purchase, and I made absolutely sure all the info is correct.

If eBay and PayPal both claim to support prepaid Visas, why am I not able to use mine? Is there a fix?