All prime accounts or no? Did all already have linked amex for shop with points?
Didn't check them all, didn't get a chance to.
Can u use same amex card for the promo across multi amazon accounts?
Meaning one MR account?
If your account is eligible for the offer and after using the same card for a 2nd account with a point doesn't trigger the offer, try another card number on the same MR program( which should work fine, as I have used multiple cc's on the same MR account and they worked fine, and for those few times I would have issues using the promo I would just call amazon and have them give me a credit manually.)