Where did I go wrong for Appcheck?

Question

I am using firebase real time database in my application. In the update 1,5 month ago, I activated appcheck in my application. Even though most users have upgraded to the new update, the appcheck data still seems to be minimal. Where did I go wrong? I manually added Firebase SHA-256 myself. Did I make a mistake there? An average of 200 people use the app every day. I activated "Play Integrity" from google play console. It looks normal there.

implementation platform('com.google.firebase:firebase-bom:30.3.1') 

    implementation 'com.google.firebase:firebase-appcheck-playintegrity'

In the application, splashscreen activity and then login activiy are opened. The main activiy opens when the user logs in. I added this code to mainactivity:

FirebaseApp.initializeApp(/context=/ this);
        FirebaseAppCheck firebaseAppCheck = FirebaseAppCheck.getInstance();
        firebaseAppCheck.installAppCheckProviderFactory(
                PlayIntegrityAppCheckProviderFactory.getInstance());