I decided to delete my Bridge pairing yesterday and restore it ... no real reason; just bored I guess. I also deleted the Bluetooth pairing between the devices.
Anyway, I had a heck of a time getting the two devices paired again on Bluetooth ... the scanning of the QR code wasn't working and the manual pairing kept crapping out when I was authenticating the devices to each other.
When you're trying to manually authenticate on Bluetooth, you have to enter the same numeric password on each ... I usually use "000" (I think). This didn't work for me yesterday, and I was getting ambiguous error messages. Finally I changed the numeric password to "1234", and authentication occurred.
Once past that stage I got the case sensitive password which the Bridge requires.