v-for中的VeuJS v模型不响应

Question

请考虑以下内容：

<ul class="park-list row row-pd">
        <li class="col-12" v-for="(item, index) in list.items" v-bind:key="index">
            <div class="park-note px-3 py-2">
                <p class="font-italic" >
                    {{ item.notes }} <a v-bind:href="'#collapseNoteTest'+item.id"
                                        data-toggle="collapse" role="button" aria-expanded="false"
                                        v-bind:aria-controls="'#collapseNoteTest'+item.id">
                    <i class="svg-12 ic-cyan-path" v-html="icons['ic-edit']"></i></a>
                </p>
                <div class="collapse" v-bind:id="'collapseNoteTest'+item.id">
                    <div class="form-group">
                        <label for="exampleFormControlTextarea1">Note:</label>
                        <textarea class="form-control" v-model="item.notes" rows="3"></textarea>
                    </div>
                    <div class="form-row">
                        <div class="col-auto ml-auto">
                            <button type="button" class="btn btn-outline-primary" v-bind:href="'#collapseNoteTest'+item.id"  data-toggle="collapse">Cancel</button>
                        </div>
                        <div class="col-auto">
                            <button class="btn btn-success mb-2" v-bind:href="'#collapseNoteTest'+item.id"  data-toggle="collapse">Save</button>
                        </div>
                    </div>
                </div>
            </div>
        </li>
    </ul>

无论我在这里做什么，当我在文本区域中输入文本时，item.notes都不会更新。我在做什么错了？