Savedinstancestate Is Null After First App Shutdown But Not After Second

I am following this codelab Android Kotlin Fundamentals 04.2: Complex lifecycle situations https://codelabs.developers.google.com/codelabs/kotlin-android-training-complex-lifecycle

Solution 1:

I believe this rounds down to Can an activity be created with saved instance state saved by an older version of the app?. The system does not believe that the activity started from the Recents screen is a continuation of the activity launched from Android Studio. Maybe it's possible to advise it otherwise by forcing taskAffinity or launchMode for your activity, but nothing will be bullet-proof. You can reproduce the whole cycle from beginning if you start by running the app from the launcher, not from Android Studio.

Also, it's important to remember:

Note:

Multiple tasks can be held in the background at once. However, if the user is running many background tasks at the same time, the system might begin destroying background activities in order to recover memory, causing the activity states to be lost.

Solution 2:

try to include onRestoreInstanceState. read more about the lifecycle here. But I dont think it save the state if you kill the app... maybe you should better use SharedPreferences?