滚动条滚动到固定列下面的时候滚动条无法滚动

<el-table :data="tableData6" border="" show-summary style="width: 100%">

<el-table-column prop="id" label="ID" width="180">
</el-table-column>
<el-table-column prop="name" label="姓名">
</el-table-column>
<el-table-column prop="amount1" sortable label="数值 1">
</el-table-column>
<el-table-column prop="amount2" sortable label="数值 2">
</el-table-column>
<el-table-column prop="amount3" sortable label="数值 3">
</el-table-column>
<el-table-column prop="amount3" sortable label="数值 3">
</el-table-column>
<el-table-column prop="amount3" sortable label="数值 3">
</el-table-column>
<el-table-column prop="amount3" sortable label="数值 3">
</el-table-column>
<el-table-column prop="amount3" sortable label="数值 3">
</el-table-column>

</el-table>
var Main = {

data() {
  return {
    tableData6: [{
      id: '12987122',
      name: '王小虎',
      amount1: '234',
      amount2: '3.2',
      amount3: 10
    }, {
      id: '12987123',
      name: '王小虎',
      amount1: '165',
      amount2: '4.43',
      amount3: 12
    }, {
      id: '12987124',
      name: '王小虎',
      amount1: '324',
      amount2: '1.9',
      amount3: 9
    }, {
      id: '12987125',
      name: '王小虎',
      amount1: '621',
      amount2: '2.2',
      amount3: 17
    }, {
      id: '12987126',
      name: '王小虎',
      amount1: '539',
      amount2: '4.1',
      amount3: 15
    }]
  };
},
methods: {
  getSummaries(param) {
    const { columns, data } = param;
    const sums = [];
    columns.forEach((column, index) => {
      if (index === 0) {
        sums[index] = '总价';
        return;
      }
      const values = data.map(item => Number(item[column.property]));
      if (!values.every(value => isNaN(value))) {
        sums[index] = values.reduce((prev, curr) => {
          const value = Number(curr);
          if (!isNaN(value)) {
            return prev + curr;
          } else {
            return prev;
          }
        }, 0);
        sums[index] += ' 元';
      } else {
        sums[index] = 'N/A';
      }
    });

    return sums;
  }
}

};
var Ctor = Vue.extend(Main)
new Ctor().$mount('#app')