Installable web app does not use icons while being installed on android

I am deploying an installable web app with web manifest and icon images are not being used when installed on Android (I have not tried other platforms).

I am following this guide: https://developers.google.com/web/updates/2014/11/Support-for-installable-web-apps-with-webapp-manifest-in-chrome-38-for-Android?hl=en

My system parameters:

index.html is available
manifest.json is avaliable and is used when "add to homescreen" is being called
App is properly installed (except for icons) - it points to the right URL and uses a standalone mode
Images are available - one of them is used as browser icon and is visible in both desktop and mobile chrome browsers
Mobile chrome version 51.0.2704.81
Android version 6.0.1
Azure web app is used to host the web app

Manifest.json

{
 "name": "Test app",
 "icons": [
  {
    "src": "icon-1x.png",
    "sizes": "48x48",
    "type": "image/png",
  }, ...

Solution

I needed to configure an icon with resolution 256, probably due to the screen size of Nexus 6.