You need to add another file, such as pref_headers.xml
since Android can also use headers to determine how to show the preferences. See the documentation.
In it, put the name of your Fragment
<preference-headers xmlns:android="http://schemas.android.com/apk/res/android" >
<header
android:fragment="com.myapp.MyFragment"
android:title="My header" />
</preference-headers>
Add more header
tags for other fragments.
Then change
loadHeadersFromResource(R.xml.prefs, target);
to
loadHeadersFromResource(R.xml.pref_headers.xml, target);