Here are some reasons why your customers may not be receiving push messages from you.
1 - Your customers don't have your card installed in Apple Wallet.
Only customers with the 'Card Status' of 'Installed' will be able to receive push messages. Simply go to your 'Customers' table and check the 'Card Status'.
If you notice that your customer's card status is 'Issued' (meaning they have signed up but have not installed their card), here's how you can send them their unique card link and tell them to install their card.
2 - Google Wallet does not currently support push notifications.
However, when you send a message to customers, they will still be able to see the message you sent under the 'Latest Updates' field on their card.