Shared preferences inactive on app exit

Question

Please help me out with my issue. I'm using preference fragment to let users choose to keep screen light on or allow the screen to go dim.

This works well when you get in preferences but once you exit app, it doesn't work on next launch.

Funny, if you open settings screen and click back, the feature works yet again until you exit app.

Would love to know how to fix this.

private void setInitialState() {
    SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
    pm = (PowerManager) getActivity().getSystemService(Context.POWER_SERVICE);
    if (sp.getBoolean(getString(R.string.keep_screen_on_key), false))  {
        startKeepScreenOn();
    } else {
        dsSwitch.setEnabled(false);
    }
}

ksoSwitch =  (SwitchPreference) 
findPreference(getString(R.string.keep_screen_on_key));
    dsSwitch = (SwitchPreference) findPreference(getString(R.string.dim_screen_key));
    setInitialState();

    ksoSwitch.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
        @Override
        public boolean onPreferenceChange(Preference preference, Object newValue) {
            if (newValue.equals(true)) {
                dsSwitch.setEnabled(true);
                startKeepScreenOn();
            }
            else {
                dsSwitch.setEnabled(false);
                wl.release();
                wl = null;
            }
            return true;
        }
    });
    dsSwitch.setOnPreferenceChangeListener(new Preference.OnPreferenceChangeListener() {
        @Override
        public boolean onPreferenceChange(Preference preference, Object newValue) {
            wl.release();
            startKeepScreenOn();
            return true;
        }
    });