Android DEFERRED downgrade fails in app, but still issues on Google Play

[fooberichu150]

Please note, I'm not sure this is even a bug that can be resolved. I am posting it to track the issue so if I decide to really dig into it on my side, I have something I can refer back to on your side. TLDR: this seems like an issue that starts on Google's side and without some magic interpretation on the app/library side, we couldn't really react appropriately to it.

Bug Information

Version Number of Plugin: 8.0.5
Device Tested On: Samsung Galaxy Note20 Ultra (Android 13)
Simulator Tested On: (can't get purchases working in the simulator for some reason)
Version of VS: VS Pro 17.11.6
Version of Xamarin: .NET Maui 8
Versions of other things you are using:

Note - this relies on my current PR for upgrade/downgrade support.

Additional note: I don't think this works on Google's side the way they claim it does. No Google Cloud pub/sub notifications are published when this goes through until the new plan first charge takes effect.

Steps to reproduce the Behavior

• Set up a subscription with an annual and a monthly base plan.
• Subscribe to the annual plan.
• Attempt to downgrade to the monthly plan using DEFERRED mode.

Expected Behavior

Plan should come back from the plugin with a DEFERRED status matching Google Play documentation:

It would be anticipated that the app could then react to the changes as per their documentation.

Actual Behavior

When the billing response comes back from the purchase flow, it returns the original purchase, not the new plan. Contrary to what Google claims, it does not issue the new purchase immediately. If you wait for the renewal period, however, Google does issue the new plan and cancel the previous plan.

Code snippet

Screenshots