This has happened twice now. The built in GPS system on my Corsa E calculates my location about a quarter of a mile out. I've put in the latest map upgrade and this seems to be since then. First time was on the drive, the second more recent towards the end of a long trip. It suddenly urged me to turn sharp right. This was on a dual carriageway without any right turns available. When I glanced at the display it showed me off the road completely.
Seems to sort itself out after a few miles of driving.
GPS glitches