Ionic 4 Tabs: view is still visible when switching the tab

I have a Tab-Bar like this:

 <ion-tabs #myTabs>

          <ion-tab-bar selected-tab="orders" slot="top" color="primary">
            <ion-tab-button tab="orders">
              <ion-icon name="clipboard"></ion-icon>
            <ion-tab-button tab="calendar">
              <ion-icon name="calendar"></ion-icon>
          <ion-tab active="true" tab="orders">
          <ion-tab tab="calendar">

In beta-version 15 I opend the app and it was automatically on the first tab and the tab was highlighted. In version 17 it changed. It was not highlighted anymore and I had to set the active=“true” flag to show the first tab. And now, the first time I switch to the second tab, the contents of the first tab is still there (in the back). When I go to the page a second time it is fine. I noticed that the first time I switch, the tab does not get the “tab-hidden” property.
I am not sure if this is a bug or not.