We're using Flask/Gunicorn/Nginx on a Google Compute Engine instance. All the SSL implementation is working, and it receives/works fine with all of our cURL tests. However, we have yet to see anything post from Apple. I added the "Subscription Status URL" to our app 2 days ago, we've had hundreds of subscription events (indicated in our analytics), but have not had any connection attempts from a legitimate server besides our tests (that we can see in our NGINX access logs).
How long does it take for Apple to start sending the notifications? Do we need to release an update to the app for it to go live?