I found this out the hard way this morning. Tried to swipe the card twice and both times, like you, I saw the "See Attendant" message. The attendant was able to swipe the card with no difficulty. As a point of reference, this was at a BP.

I called Amex to see what was up and the CSR immediately noted that I had the new card with the chip and indicated that they were having problems with pay at the pump transactions and that they were working on a fix.