Help with using an Amex Gift Card

Description

Good afternoon. I’m having issues using an Amex Prepaid Giftcard. I’ve used them for a couple years now on Paypal and never had a problem until now. I got a $1000 card from work for an Xmas bonus, and made a transaction last night in the amount of $400. It went through just fine. But when I tried using it today, it stated that the card couldn’t be used and to try a different card. I have since tried many times and keep getting the same message. I’ve checked the balance, I know there is enough left on the card for a fact. So what is the deal here, can anyone shed some light on this for me please? Thank you, I appreciate any help. This is extremely frustrating.