Support Assist not updating- CHECK INTERNET CONNECTION message

When I attempt to open Support Assist on my XPS 7390 I get the message that an update is available. When I attempt to install it I consistently get the msg UPDATE FAILED - CHECK INTERNET CONNECTION. 

The internet connection is fine (it's ) and has not no issues in recent times.

So I have removed Dell Support Assist and attempted to re-install it, only to get the same msg.

Any suggestions?

I've seen a couple of posts saying I should remove other Dell update apps but I'm reluctant to do so.