Ionic 4:'desktop') returns wrong value when installed apk in android 4.4.4

I have created an app using Ionic 4 and built android app with below code .

alert('desktop ' +'desktop'));

When I installed an app in android 4.4.4 version device and emulator, it is showing the alert value as true whereas In other higher OS version device it is showing as false .

I have used platform condition at so many places in my code. Because of the above issue code is breaking in android 4.4.4 devices.

I am not able to understand why it is showing desktop platform as true in android kitkat device?

ionic info :


   ionic (Ionic CLI)             : 4.12.0 (C:\Users\user1\AppData\Roaming\npm\node_modules\ionic)
   Ionic Framework               : @ionic/angular 4.4.2
   @angular-devkit/build-angular : 0.13.9
   @angular-devkit/schematics    : 7.3.9
   @angular/cli                  : 7.3.9
   @ionic/angular-toolkit        : 1.5.1


   cordova (Cordova CLI) : 9.0.0 (cordova-lib@9.0.1)
   Cordova Platforms     : android 8.0.0
   Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 4.0.1, (and 4 other plugins)


   Android SDK Tools : 26.1.1 (C:\Users\user1\AppData\Local\Android\sdk)
   NodeJS            : v10.14.2 (C:\Program Files\nodejs\node.exe)
   npm               : 6.4.1
   OS                : Windows 10

Can anyone please provide any solution to this issue?