Hard to say what the issue is with the info provided here. What version of the webview are you running where things are broken? You can find this by logging window.navigator.userAgent when inspecting the app with dev tools.
Additionally, I noticed you are using Android 8.1.0. Are you using the <ion-icon> component at all? Another developer is running into a Chromium bug on certain devices where SVG icons cause the webview to render incorrectly (See: Android 8.1 Icons not displaying).