Self Hosted extension missing icon on google admin console

[Thomas Asmerom]

I have a self-hosted application that is hosted on a nonwebstore server. 
Even though the application is managed installed to users and working as expected.

However as the picture above on the Google admin page under  DevicesChromeApps & extensions the extension icon or logo is missing.

Note the extension is built with manifest icons 16,  48, and 128 sizes. 

Extensions from webstore have icons displayed with them on Google admin console. However, self-hosted extensions by URL miss to display their icons, making it difficult to find the right extension after hosting several self-hosted extensions.

Is there something I am missing in how to host the extension. I appreciate your help :)