My Haibike failed this morning with this problem ("Shutting Down" hang) , just as I was loading the bike up for an important ride.
The dealer recommended plugging the head unit into a usb charger for an hour to fix it. It didn't. I had to open up the unit, unsolder a battery wire, resolder it (hard reboot) and it worked. Opening the unit is probably a warranty voider: 2 of the screws are epoxied- I had to pick out as much as I could with a dental tool and still couldn't remove one of the screws. I finally had to drill it out carefully using 2 different drill bits.
Once it was working, it had defaulted to km, but all the other setting were ok.
I may install a switch or pack a butane soldering iron in my bike kit...?
Paul