I’ve found bug in 168 line of file “Engine/Build/Android/Java/src/com/epicgames/ue4/GooglePlayStoreHelper.java”. ReadInAppPurchaseInformation currently query only purchased items and not all available items.
It’s currently:
inAppPurchaseHelper.queryInventoryAsync(GotInventoryListener);
but should be this for query all items:
inAppPurchaseHelper.queryInventoryAsync(true, Arrays.asList(cachedQueryProductIds), GotInventoryListener);
More about this method you can find here: Visão geral do sistema de faturamento do Google Play | Sistema de faturamento do Google Play | Android Developers