queryProductDetails() from InAppPurchase package awaits forever and never returns after integrating purchases_flutter

purchases_flutter: latest

in_app_purchase: latest

Platform: Android

Framework: Flutter
Problem:
After adding purchases_flutter to a Flutter project that already used in_app_purchase, this call queryProductDetails() freezes indefinitely and never resolves:

final ProductDetailsResponse response = await InAppPurchase.instance .queryProductDetails(productIds);