下拉刷新如图，模拟器正常，真机上不回弹。上拉加载，切换到其他页面时，如果没有数据或者上拉的动作，就一直显示加载中，这问题怎么解决，求助大佬

wxml代码
<view class="carpool-title">
  <text class="title-text">百姓同城拼车网-同城拼车</text>
</view>
<view class="ad-group">
  <image class="ad-image" src="../../images/专注.jpg" mode="" />
</view>
<view class="search-input-group">
  <view class="input-group">
    <input class="search-input" placeholder="出发地" />
    <image class="thumbnail" src="../../images/return.png" mode="" />
    <input class="search-input" placeholder="终点" />
  </view>
  <button class="search-button" size="mini">查询</button>
</view>


<segment-carpool items="{{items}}" wehicle="{{wehicle}}" binditemchengde="onItemChengdeEvent" defaultIndex="0">
  <view slot="0" class="segment-page wehicle-page">
    <wehicle wx:for="{{wehicles}}" wx:key="wehicle" wx:for-item="wehicle" wehicle="{{wehicle}}"></wehicle>
  </view>
  <view slot="1" class="segment-page people-page">
    <wehicle wx:if="{{wehicle.carpool == '我要找车'}}" wx:for="{{wehicles}}" wx:key="wehicle" wx:for-item="wehicle" wehicle="{{wehicle}}"></wehicle>
  </view>
  <view slot="2" class="segment-page train-page">
    <wehicle wx:if="{{wehicle.carpool == '我要找人'}}" wx:for="{{wehicles}}" wx:key="wehicle" wx:for-item="wehicle" wehicle="{{wehicle}}"></wehicle>
  </view>
  <view slot="3" class="segment-page money-page">
    <wehicle wx:if="{{wehicle.carpool == '我找货车'}}" wx:for="{{wehicles}}" wx:key="wehicle" wx:for-item="wehicle" wehicle="{{wehicle}}"></wehicle>
  </view>
  <view slot="4" class="segment-page money-page">
    <wehicle wx:if="{{wehicle.carpool == '我要找货'}}" wx:for="{{wehicles}}" wx:key="wehicle" wx:for-item="wehicle" wehicle="{{wehicle}}"></wehicle>
  </view>
</segment-carpool>
<loadingmore hasmore="{{hasmore}}"></loadingmore>

JS代码
const db = wx.cloud.database();
Page({
  data: {
     items:["全部","我要找车","我要找人","我找货车","我要找货"],
     hasmore:true,
     wehicles:[],
  },
  onLoad(options) {
    
  },
  onItemChengdeEvent(event){
    
  },
  lowdrelease(start=0){
    const that = this;
    let promise = db.collection("wehicle");
    if(start>0){
      promise = promise.skip(start);
    }
    promise.limit(10).orderBy("create_time", "desc").get().then(res => {
      const wehicles = res.data;
      let hasmore = true;
      if(wehicles.length == 0){
        hasmore = false
      }
      let newWehicles = [];
      if(start > 0){
        newWehicles = that.data.wehicles.concat(wehicles);
      }else{
        newWehicles = wehicles;
      }
      that.setData({
        wehicles:newWehicles,
        hasmore:hasmore
      })
    })
  },
  /**
   * 生命周期函数--监听页面显示
   */
  onShow() {
    this.lowdrelease();
    wx.stopPullDownRefresh();
  },
  /**
   * 页面相关事件处理函数--监听用户下拉动作
   */
  onPullDownRefresh() {
    this.lowdrelease(0);
  },
  /**
   * 页面上拉触底事件的处理函数
   */
  onReachBottom() {
    this.lowdrelease(this.data.wehicles.length);
  },
})