Android Auto says "It is Offline"?

what I mean is once I am way clear of the house. the phone is using cellular data so if using USB it should still be switching to this, which is does. if wireless I would assume the phone to use cellular by default?

I believe I have read this is an issue for the s20 phones? if you believe you know where the setting I need to change is please share?
 
When you use wireless AA, it defaults to cellular data connection as WiFi is occupied by AA connection.

I would not trust wireless AA on anything other than Google's own Pixel phones. Let Google and OEMs work out the bugs. Google only allowed non-Pixel phones to use wireless AA late last year and I heard nothing but problems with it. There isn't must user configurable settings. It just plain doesn't work well.
 
its a shame as I was having a good experience on my s9 plus other than replying to messages which I hear is a common issue! im surprised how slow they are to fix these issues!

i.e. dark mode took ages to get fixed!