android - Achievements not showing in Google Play Games App

We implemented the Google Play achievements for our Android game according to the official google development documentation, but there seems to be something off, as we notice the following strange

Android Developers Blog: Improvements for smaller app downloads on

Mowing Mazes Google Play Games Help - Protostar Games

Terraria Google Play achievement not working - Google Play Community

Google Play Games FAQ, Android game development

Test and publish your game, Play Games Services

android - Displaying Google Play Achievements - Stack Overflow

android - Achievements not showing in Google Play Games App

Google Play - Wikipedia

android - Google Achievement XP is not showing in Achievements and