Parent Acitivity's status not kept when backing from child activity - android-activity

Question

In AndroidManifext.xml, I have :
<activity
android:name=".mypackage.ChildActivity"
android:label="Child"
android:parentActivityName=".mypackage.ParentActivity"
android:screenOrientation="portrait"
android:windowSoftInputMode="stateHidden|adjustResize">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value=".view.activities.ParentActivity" />
</activity>
Inside ParentActivity, I have a few fragements, A, B, C. At fragment C, I launch ChildActivity when clicking a button. When backing to ParentActivity, I am not landing on Fragment C, but Fragment A. It appears that ParentActivity is relaunched or initialized again.
In ChildActivity, I have:
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
As a comparison, I also tried to replace ChildActivity with a Fragment D and backing from fragment D correctly lands on fragment C.
Where did I miss for the ChildActivity implementation?
Edited:
Just noticed that when clicking "Back" button on device, it properly backs to Fragment C of ParentActivity, but if hitting the "<" button at the left top corner in Child Activity, that's where issue arises.
Thanks in advance!
Shawn

Answer 1

Remove the mentioning parent from your childActivity. Like below. Because android already maintains the stack of navigations
<activity
android:name=".mypackage.ChildActivity"
android:label="Child"
android:parentActivityName=".mypackage.ParentActivity"
android:screenOrientation="portrait"
android:windowSoftInputMode="stateHidden|adjustResize">
</activity>