Chime Pro stuck on update routine

Chime Pro 2nd Gen stuck on update routine. It logs on tp wifi ok but then starts flashing blue/green and app says it is updating and could take up to 15 minutes. I've left it for 2 hours and it still says updating. I've tried holding reset button 5/10/20/30 seconds and nothing changes, it still flashes blue/green. I've tried to set it up at a friends house on a totally different network where it connects to thier wifi ok but then goes in to same update mode and stays there. Any ideas what I can do to get it back to normal operating mode??