Component used: Navigation

Version used: 2.6.0-beta01, 2.6.0-SNAPSHOT

Devices/Android versions reproduced on: All devices

Related issue https://issuetracker.google.com/issues/279306628

14:43:44.151 20993-20993 AndroidRuntime           E  FATAL EXCEPTION: main
	Process: com.example.navigationissue, PID: 20993
	java.lang.IllegalArgumentException: The fragment SimpleFragment{ea1a1bc} (d8278311-d056-4068-ac70-fccb783b0731 id=0x7f080132 tag=3509fe8d-2b8f-41d6-ac7c-b15ea21e5a4c) is unknown to the FragmentNavigator. Please use the navigate() function to add fragments to the FragmentNavigator managed FragmentManager.
	at androidx.navigation.fragment.FragmentNavigator$onAttach$2.onBackStackChangeCommitted(FragmentNavigator.kt:147)
	at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1918)
	at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1845)
	at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1782)
	at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:565)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loopOnce(Looper.java:201)
	at android.os.Looper.loop(Looper.java:288)
	at android.app.ActivityThread.main(ActivityThread.java:7842)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)

Sample project to trigger the issue requested as attached. Fragment of interest here is SimpleFragment.kt

Project has 1 main graph that includes 3 sub nav graphs, each sub graph with a single fragment with a button.

main_graph
navigation_start
navigation_simple
navigation_second

Navigation flow.

Start -> Simple -> Second. Second pop back to Simple either by Android Back or button click.
Simple onResume will trigger a navigation back to Start by reacting to a state change.
Crash occurs with the exception above

Crash doesn't occur 2.6.0-alpha09 and below. Or if navigation doesn't happen within onResume callback by moving navigation call to button click.

Scenario is the top level fragment triggered a fragment result state back to bottom fragment after performing some business logics.