Recently I found an InTune pc having issues deploying software and PowerShell 

In the “Company Portal” Store App it showed there was a: Delay in Downloading files error

I then found there was no Management Extension Application Service installed as all

This can be manually downloaded and installed from here : 

https://prodamsub0102data.azureedge.net/IntuneWindowsAgent.msi 

After installing , software started Deploying