Different Android Id in Android 10

Question

I have used two application from playstore named "Device Id" and one self made apk to fetch android id using SECURE.ANDROIDID but every time I am getting different android id(device id) in Android 9 and 10. Though it is coming same for Android 5 and 7.

What can be the reason for this?

Answer 1

Making ANDROID_ID change is a deliberate privacy feature added in Android 8.0:

For apps installed on a device running Android 8.0, the value of ANDROID_ID is now scoped per app signing key, as well as per user. The value of ANDROID_ID is unique for each combination of app-signing key, user, and device. As a result, apps with different signing keys running on the same device no longer see the same Android ID (even for the same user).