I added my FitBit Versa to trust devices without problem. Then I noticed that I still had to enter my PIN after screen blackout. So I looked at trusted device list and the Versa wasn't there. So I tried to add it again and it showed the device as availalble but when I tapped on it there was no option for adding it, only "Learn More' and "CANCEL'. The Versa works okay; it is still communicating health to my FitBit app on the phone.
I also added my home and my office to trusted locations. Here I am at my OFFICE ant I STILL have to enter the PIN after screen blackout.