Support Assistant wont install

I have been struggling to install support assistant on my PC.

Each time it runs, i get the below error 'This PC needs to be online to continue...'

I have tested on bot the WiFi and tethered to my phone. In all cases I have had a good internet connection.

The device is not behind a firewall, nor is antivirus blocking any network traffic.

Any advice on what I should check would be great!