I was trying to use my biz plat credit so it was first time using the card on the account, but it also didn't work as a guest. I called customer support and said my (legitimate) orders keep getting cancelled and they said it was a "verification issue" and had to get approval but eventually reinstated. They did ask while they submitted the approval "Oh are you a resale business?" And I played dumb but my next legitimate order went through. Maybe I'll try again after I use my amex credits for the year but don't wanna take the risk until then.