App Store Server Notifications V2 for FAMILY_SHARED subscriptions dot not fully arrive in Sandbox

Hi,

We are implementing App Store Server Notifications V2 and currently testing the implementation in Sandbox.

For inAppOwnershipType PURCHASED subscriptions we are getting all server notifications for any subscription change up until eventual expiration/cancellation.

For FAMILY_SHARED subscriptions we are expecting the notifications we get to mimic same behavior as for PURCHASED inAppOwnershipType subscriptions, while in reality the following behavior occurs:

1. Account gets access to subscription through family sharing
2. We get only 2 notifications for FAMILY_SHARED subscription - INITIAL_BUY and RENEWAL
3. We do not get any more notifications for said subscription - even when it, for example, expires.

Is this behavior expected in Sandbox? Will it work differently in Production environment?

(We do have cronjobs that sync data on a specific interval with the app store APIs, but we've been relying on server notifications as a main source of information for subscription changes because it is near realtime, with this limitation our architecture might need to change)

Thanks!