While testing IAP subscription Webhooks via the sandbox, we are receiving inconsistent webhooks from apple.
In every subscription we trigger, the initial payment hook is received as expected. Following the initial payment our server only receives 1-3 of the expected 6 renewal webhooks. After the final renewal should have arrived, verifying the initial receipt shows the complete list of renewals, including ones we never received webhooks for.
At this point, we have covered every base we can think of that could be masking webhooks from us, including watching their receipts via nginx logs instead of waiting until they are processed by our backend.
Is this expected behavior on the test environment? Is there another solution we should be looking at?
