App Store Server Notifications not sent

I'm encountering an issue with App Store Server Notifications V2 not being delivered for in-app purchases, even though test notifications work perfectly.

On Staging environment everything works as expected. But purchases on production are not arriving. I ran a AppStore Test notification today to ask App Store Server Notifications to send a test notification to my server. And it worked.

Despite the test notification working, Apple is not sending any actual purchase-related notifications to my server. When I query the notification history endpoint using the proper millisecond timestamps:

POST /inApps/v1/notifications/history
{
  "startDate": 1746887752000,
  "endDate": 1747386755000
}

I get an empty response:
{
  "notificationHistory": [],
  "hasMore": false
}

That means it never even attempted to do send anything historically. The timestamps cover the period from my first purchase (May 10, 2025) to present day. I've verified these timestamps are correctly formatted in milliseconds.

After the successful Test notification, I can see one entry in the production history. But the previous purchases never triggered anything.

Multiple purchases have been made on production in the last 6 days. I didn't store the receipts, thinking that I could rely on these server notifications.

What could be the issue, please?

Thanks