Slot Footer Not Working with Transition Group

Everything works, except when I try to add a non-draggable item with footer within a transition-group like this:

      <draggable v-model="myList" :options="{draggable:'.item'}">
        <transition-group name="animated-list">
          <div v-for="element in myList" :key="element" class="animated-list-item item">
              <book :beat.sync="books[element]"></book>
          </div>
          <button slot="footer" key="button">Add Another Book</button>
        </transition-group>
      </draggable>

If I remove transition-group it works as expected.

[David-Desmaisons]

It is not supported inside a transition-group.

[David-Desmaisons]

On second thought, I was abble to make it work, see update footer example: https://sortablejs.github.io/Vue.Draggable/#/footerslot