title: ion picker options overlaps
body: <p>Currently, I am working on a ionic application which require <a href="https://ionicframework.com/docs/api/picker" rel="nofollow noreferrer">ion-picker</a> (multi column picker). </p>
  
  <p>I got the data perfectly as I want but just one time means when I open picker for the first time, but after that when I click second time the all options overlapped, I am not able to upload image because of stackoverflow (10 reputation) policy. so please refer the example <a href="https://github.com/ionic-team/ionic/issues/15579" rel="nofollow noreferrer">here</a>
  , I have also tried <code>selectedIndex: 0</code> as suggested in the GitHub link but nothing change.please let me know if anyone know how to solve this. </p>
  
  <p>Thanks in advance</p>
  
  <pre><code>var myColumns = [
          {
              name: "days",
              options: this.day2,
              selectedIndex: 1
          },
          {
              name: "Hours",
              options: this.hours2,
              selectedIndex: 1
          },
          {
              name: "Minutes",
              options: this.minutes2,
              selectedIndex: 1
          },
          {
              name: "dayType",
              options: this.HourType,
              selectedIndex: 1
          }
      ];
      const picker = await this.pickerCtrl.create({
          buttons: [
              {
                  text: "Done"
              },
              { text: "Cancel" }
          ],
          mode: "md",
          cssClass: ["datePicker"],
          columns: myColumns
      });
  </code></pre>