I have integrated Google Play Games by adding this dependency to my build.gradle:

implementation 'com.google.android.gms:play-services-games:22.0.1'

The correct javadoc .jar file seems to be attached to the Google Play libraries in Android Studio (I checked in Project > External libraries > Library properties)

On my PC it's a valid file located at C:\Users\myusername\.gradle\caches\modules-2\files-2.1\com.google.android.gms\play-services-games\22.0.1\9f45822a5bacdc3094d84a49cdbf48bbac45f738\play-services-games-22.0.1-javadoc.jar

Yet the documentation works correctly on some code...

...but fails on most methods:

AS states that The following documentation urls were checked: ...

How can this be fixed?