Android - BillingClient returns empty purchases list

Question

Some of my users tell me that my app forgets the purchased subscriptions every now and then. It works for 3-4 days and then it forgets them. This is a very important issue as users might suspect fraud. I am using billing library 4.0.0 and I have implemented the billing logic as per Google's guidelines.

From what I have gathered it happens when for some reason the billing service connection is interrupted. (Play Store is updating for example)

I have managed to replicate this scenario the following way

- Disable internet connection
- Clearing Play Store app data
- Fresh launch of my app.
- Call billingClient.startConnection()
    onBillingSetupFinished called with responseCode BILLING_UNAVAILABLE
    user sees -> The app says "no subscription purchased"

- Enable internet connection
- re-initialize BillingClient.
    onBillingSetupFinished called with responseCode OK. billingClient.isReady() returns true. 
- Call billingClient.queryPurchasesAsync() and billingClient.querySkuDetailsAsync().
    onSkuDetailsResponse is called with the skuDetailsList filled with all the proper data. However:
    onQueryPurchasesResponse is called with empty purchase list -> Again user sees "no subscriptions purchased"

Important If at this point I open Play Store it shows the purchased subscriptions. But the app still gets an empty purchases list.

If I keep calling billingClient.startConnection() or billingClient.queryPurchasesAsync() at some point after about 10 minutes one attempt will succeed and return a non empty purchases list.

Is it possible to tell Play Store to refresh its subscription data for my app? How can someone handle this scenario gracefully ?

Answer 1

You need to call acknowledgePurchase for every purchase.
See the official docs and the article for more details.

Answer 2

Worked for me!

BillingClient billingClient = ...;

billingClient must be ready -> billingClient.isReady() == true;

So, always call billingClient.queryProductDetailsAsync(...) from

                @Override
                public void onBillingSetupFinished(BillingResult billingResult) {
                    if (billingResult.getResponseCode() == BillingClient.BillingResponseCode.OK) {
                        // The BillingClient is ready. You can query purchases here.
                        queryProductDetails();
                        queryPurchases();
                    }
                }

when initialize the billingClient connection! Keep it up :)