Modal组件打印了以下错误

我发现如果不用teleport就没有问题。或者在原有的emits数组中（[‘modal-on-close’, ‘modal-on-confirm’]）加上错误信息中所说的’modalOnClose’, 'modalOnConfirm’两个事件也没有问题。我在父组件中和Modal中仍然全部用的是kebab。请问这是什么原理啊。
Modal组件的代码

<template>
  <teleport to="#modal">
    <div class="modal d-block" tabindex="-1" v-if="visible">
      <div class="modal-dialog">
        <div class="modal-content">
          <div class="modal-header">
            <h5 class="modal-title">{{title}}</h5>
            <button type="button" class="close" data-dismiss="modal" aria-label="Close" @click.prevent="onClose">
              <span aria-hidden="true" >&times;</span>
            </button>
          </div>
          <div class="modal-body">
            <slot></slot>
          </div>
          <div class="modal-footer">
            <button type="button" class="btn btn-secondary" data-dismiss="modal"  @click="onClose">取消</button>
            <button type="button" class="btn btn-primary"  @click="onConfirm">确定</button>
          </div>
        </div>
      </div>
    </div>
  </teleport>
</template>

<script lang="ts">
import { defineComponent } from 'vue'
import useDOMCreate from '../hooks/useDOMCreate'

export default defineComponent({
  props: {
    visible: {
      type: Boolean,
      required: true,
      default: false
    },
    title: {
      type: String
    }
  },
  // 报错
  emits: ['modal-on-close', 'modal-on-confirm'],
  // ok
  // emits: ['modal-on-close', 'modal-on-confirm', 'modalOnClose', 'modalOnConfirm'],
  setup (props, context) {
    useDOMCreate('modal')
    const onClose = () => {
      context.emit('modal-on-close')
    }
    const onConfirm = () => {
      context.emit('modal-on-confirm')
    }

    return {
      onClose,
      onConfirm
    }
  }
})
</script>

PostDetail的template中对Modal的引用

<modal title="删除文章" :visible="modalIsVisible"
   @modal-on-close="modalIsVisible = false"
   @modal-on-confirm="hideAndDelete"
 >
   <p>确定要删除这篇文章吗？</p>
 </modal>

其实都是照抄课上的代码，而且在别的类似组件中（message）也没有类似的报错