Field.set does not update the value

I have assigned an annotation to my field, namely SubDocument. Saving and loading is not a problem.

Under the method read() I say dataSetting.currentValue(value); This all works and also the variable value has the correct value. This is followed by the call field.set(classObject, dataSetting). The variable dataSetting should now update the field.

Debug results:

As you can see, the variable value contains the value "Übersicht2" and it is set successfully. When debugging field.set(classObject, dataSetting), you can also see that the currentValue=Übersicht2

Now the problem is that if I call the field via the variable and call the method #getCurrentValue, I still get back null.

Thank you for any help.

Field:

    @SubDocument(save = "master_inventory_title", read = "master_inventory_title")
    private final DataSetting<String> title = new DataSetting<String>().builder()
            .defaultValue("Übersicht")
            .build();

How I update:

    private void initSubDocuments() {
        for (Class<?> clazz : reflections.getTypesAnnotatedWith(Document.class)) {
            YamlConfiguration config = getConfig(clazz);
            if (config == null) continue;

            for (Field field : clazz.getDeclaredFields()) {
                SubDocument subDocument = field.getAnnotation(SubDocument.class);
                if (subDocument == null) continue;

                try {
                    Constructor<?> constructor = getEmptyConstructor(clazz);
                    if (constructor == null) continue;

                    Object classObject = constructor.newInstance();
                    boolean isAccessible = field.canAccess(classObject);

                    field.setAccessible(true);

                    Object dataObject = field.get(classObject);

                    if (dataObject instanceof Setting<?>)
                        loadSetting((Setting<?>) dataObject, clazz, classObject, field, subDocument, config);

                    if (dataObject instanceof OptionSetting<?>)
                        loadOptionSetting((OptionSetting<?>) dataObject, clazz, classObject, field, subDocument, config);

                    if (dataObject instanceof DataSetting<?>) {
                        loadDataSetting((DataSetting<?>) dataObject, clazz, classObject, field, subDocument, config);

                    }


                    field.setAccessible(isAccessible);
                } catch (IllegalAccessException | InstantiationException | InvocationTargetException e) {
                    throw new RuntimeException(e);
                }

                this.subDocuments.add(subDocument);
            }
        }
    }
    private void loadDataSetting(@NotNull DataSetting<?> dataSetting, @NotNull Class<?> clazz, @NotNull Object classObject, @NotNull Field field, @NotNull SubDocument subDocument, @NotNull YamlConfiguration config) throws IllegalAccessException {
        save(subDocument, config, clazz, dataSetting.getDefaultValue());
        read(null, null, dataSetting, field, subDocument, classObject, config.get(subDocument.read()));
    }

    private <T> void save(@NotNull SubDocument subDocument, @NotNull YamlConfiguration config, @NotNull Class<?> clazz, @NotNull T defaultValue) {
        if (!subDocument.save().equals("unknown") && !config.isSet(subDocument.save())) {
            config.set(subDocument.save(), defaultValue);
            saveConfig(clazz);
        }
    }

    private void read(@Nullable Setting<?> setting, @Nullable OptionSetting<?> optionSetting, @Nullable DataSetting<?> dataSetting, Field field, SubDocument subDocument, Object classObject, Object value) throws IllegalAccessException {
        if (setting != null && !subDocument.read().equals("unknown")) {
            setting.currentValue(value);
            field.set(classObject, setting);
            return;
        }
        if (optionSetting != null && !subDocument.read().equals("unknown")) {
            optionSetting.currentValue(value);
            field.set(classObject, optionSetting);
            return;
        }
        if (dataSetting != null && !subDocument.read().equals("unknown")) {
            dataSetting.currentValue(value);
            field.set(classObject, dataSetting);
        }
    }