Ah, so this is what is was?!
Yesterday I drove a short distance to Aldi, I had my hotspot on cos my wife was using it for her phone, so the car was also connected to it.
When back to the car after shopping, the screen was off and buttons not lit up so I tried restarting the car. Then the screen showed the "System update completed" message.
From there it was a nightmare as the Google maps and Waze navigation were broken, it would not find a route or if connected the phone after starting the route, it would cancel the navigation within 15 seconds.
I had to find a video on how to access a diagnostics mode to do a system reboot, luckily that fixed it.
Very hit and miss from Honda