Android - startActivityForResult immediately triggering onActivityResult

Additionally make sure the intent does not have the Intent.FLAG_ACTIVITY_NEW_TASK set.

From the docs:

This flag can not be used when the caller is requesting a result from the activity being launched.

You can't use startActivityForResult() if your activity is being launched as a singleInstance or singleTask. standard or singleTop launch mode will fix the problem.

I have seen this behavior before, please make sure your destnation activity (that special activity) is not singleInstance in AndroidManifest file. If the Activity is singleInstance, then it will return RESULT_CANCELED before launched!