Hi,
Try usiing the 'nopause' option on the app.CreateWebView() method. This should work, but I've not tested it on Android 10 or 11 yet.
Webviews will be paused when the app looses focus normally, but using the 'nopause' option will allow the webview to keep running while the app is in the background. However Android may still decide to shut down your app when it is in the background. You could try creating a foreground service using a Service.js file and that might stop Android from shutting down your app.
Be aware that Google will suspend your App if you use this technique to allow playing of Youtube videos in the background (they now charge for this privilege)