The software for the bluetooth firmware update is not compatible with new versions of mac (specifically, macOS Catalina). Appears to work on Mojave.
I wanted to update firmware because my device (Bose SoundLink III) was not being recognized as a speaker with the iPhone 11. It is connecting successfully via bluetooth, it just won't play sound. This may be a compatibility issue across the board with the introduction of AirPlay.
Leave it to Apple to fix 1 thing and break 6 others.