The loading mask of element causes the scroll bar to disappear and the page shakes

One, the phenomenon

2. Cause analysis

The reason is that the mask during loading is full screen. Cause the scroll bar to disappear, which causes the page to jump.
The loading of element ui can turn off this full screen:

let loadingInstance = Loading.service({
    
    
      lock: true,
      text: '请稍候',
      spinner: 'el-icon-loading',
      background: 'rgba(0, 0, 0, 0.7)',
      fullscreen:false
    });

This is it:

fullscreen:false