[Ionic 4] Why does my app look irregular in phone?

The toolbar is not normal. But it looks normal in the browser. And when i click back button, the app can’t exit

It’s normal again when i update my system webview, but if in other phone, do we have to update too? If necessary, what if the webview hasn’t been updated?

HI Vicky,
Bydefault the mobile web browser view is normal, unless you have changed the web browser view as system view. Please conform with that.