Apple Pay Sandbox, macOS, canMakePaymentsWithActiveCard false

Hello,

Here's some sample Javascript code:

if (window.ApplePaySession) {
    console.log('ApplePaySession is available');

    console.log('canMakePayments: ' + ApplePaySession.canMakePayments());

    ApplePaySession.canMakePaymentsWithActiveCard(merchantId)
        .then(function(canMakePayments) {
            console.log('canMakePaymentsWithActiveCard: ' + canMakePayments);
        });
} else {
    console.log('ApplePaySession is not available');
}

I'm logged into macOS with a sandbox test account that has Apple Pay permissions. The merchantId value is the one listed with my merchant ID. I'm running this locally. canMakePayments returns true, but canMakePaymentsWithActiveCard always returns false.

I have two test cards setup in the macOS account's Apple Pay wallet, and both have a billing address setup.

What can I do to troubleshoot why ApplePaySession.canMakePaymentsWithActiveCard is returning false?