Почему недействительная обратная связь в тимелеафе не работает

<!-- AddStore Modal -->
<div class = "modal fade" id = "AddUserModal" tabindex = "-1" role = "dialog" aria-labelledby = "deleteModalLabel"
     aria-hidden = "true">
    <div class = "modal-dialog" role = "document">
        <div class = "modal-content">
            <div class = "modal-header">
                <h5 class = "modal-title" id = "AddUserModalLabel">Add Store Form</h5>
                <button class = "close" type = "button" data-dismiss = "modal" aria-label = "Close">
                    <span aria-hidden = "true">×</span>
                </button>
            </div>
            <div class = "modal-body">
                <form autocomplete = "off" action = "#" th:action = "@{/stores/add_store}"
                      th:object = "${store}" method = "post"
                      role = "form" id = "addModalForm">
                    <div class = "form-row">
                        <div class = "form-group col-md-6">
                            <label for = "addstoreName">Store Name</label>
                            <input type = "text" class = "form-control" id = "addstoreName" th:field = "*{storeName}"
                                   required = "required"/>
                            <div class = "invalid-feedback">
                                Please provide a store name.
                            </div>
                        </div>
                    </div>
                    <div class = "form-row">
                        <div class = "form-group col-md-6">
                            <label for = "addStatus">Status</label>
                            <select id = "addStatus" class = "form-control" th:field = "*{status}">
                                <option th:value = "Ready_to_service">Ready to service</option>
                                <option th:value = "Temporarily_closed">Temporarily closed</option>
                                <option th:value = "Closed">Closed</option>
                            </select>
                        </div>
                    </div>
                    <div class = "modal-footer">
                        <button class = "btn btn-secondary" type = "button" data-dismiss = "modal">Cancel</button>
                        <button class = "btn btn-success" type = "submit" th:text = "Save"></button>
                    </div>
                </form>
            </div>
        </div>
    </div>
</div>