Difficulty connecting Nothing Phone 2a as Satnav

I have a 2018 Petrol Estate, with what I believe is the Bolero infotainment screen - no built-in satnav but happily accepted being plugged into my Samsung Galaxy Android phone.
When I bought the car a couple of years ago and plugged in, that more or less set itself up.

I've just swapped to a Nothing Phone 2a, also Android, largely because the connection/charging socket on the Samsung was getting less and less reliable, and sometimes dropped contact halfway round a roundabout. (It wasn't just in the car, nor with that cable, its contact was unreliable with other cables too in other places.)

Sadly the Nothing phone, while it cheerfully says it's charging, so I guess the physical connection is good, doesn't appear to want to connect to the app for navigation. For some reason the screen now identifies something as "142" which it didn't offer before, but still below that offers me the green rectangles labelled with Android or Mirror connection. When it was in a good mood, just plugging the Samsung in was enough, once it had established what it was. Now I get a pause, then "connection failed".

So - firstly - is anyone else using a "Nothing" phone successfully?
Secondly - Any suggestions for how to get it talking as a satnav, seeing as that was a large point of buying it, would be most gratefully received, please.

Note: DInosaur level tech jargon only, please !

Many thanks.

Richard,