Q: adding Amex card to apple pay in canada

Yes, that could well be the problem. You will probably need to make a choice of whch region and which card you're going to use.

You cannot use Apple pay in more than one region and with cards from different regions.  Either load the Canadian card and remove the American card or vice versa.  You cannot use both in Apple pay.

Peter Edwards1 wrote:

 

I had changed the iPhone location back to Canada before I attempted to add the Canadian Amex card. I do not want to remove the US cards that I have already added to Apple Pay because they are less secure than the Canadian card with a chip.

Amex replaced my card with one with a chip. Perhaps they're doing a gradual roll out. Contact them as see if they can replace yours.

Submit feedback to Apple here:

http://www.apple.com/feedback

Apple pay is not available in Canada yet. You won't be able to add the card at this time. Regardless what region is selected on your iPhone.

it will be officially announced when it's launched.