MultiSelectListPreference onPreferenceChange() method getting wrong parameters

I have an Android app with a MultiSelectListPreference, and I'm using the onPreferenceChange() method to update the Preference's summary. I've managed to write the code that updates the summary based on the newValues parameter, but the contents of the Object do not match the actual options selected by the user.

Here is my code:

public boolean onPreferenceChange(Preference preference, Object newValue) {
    if (preference instanceof MultiSelectListPreference) {
        List<String> newValues = new ArrayList<>((HashSet<String>) newValue);

        MultiSelectListPreference pref = (MultiSelectListPreference) preference;
        ArrayList<String> newSummary = new ArrayList<>();

        ArrayList<CharSequence> values = new ArrayList<>(Arrays.asList(pref.getEntryValues()));

        for (int i = 0; i < newValues.size(); i++) {
            int currentIndex = findIndexOfString(values, newValues.get(i).replaceAll(" ", ""));

            String title = (currentIndex >= 0) ? pref.getEntries()[currentIndex].toString().replaceAll(" ", "") : "";

            newSummary.add(title);
        }

        pref.setSummary(TextUtils.join(", ", newSummary));
    }

    return true;
}

private static int findIndexOfString(List<CharSequence> list, String s) {
    for (int i = 0; i < list.size(); i++) {
        if (s.equals(list.get(i).toString().replaceAll(" ", ""))) {
            return i;
        }
    }

    return -1;
}