Leaving this post for historical purposes, but this problem was solved with newer versions of BlueToolFixup.kext. -------------------------------------------------------- I was reading brcmpatchram issues for Monterey which lead me to re-read the Acidanthera doc here. I saw this explanation which may indicate that I'm incorrectly using BluetoolFixup   BlueToolFixup.kext Required for macOS 12 or newer, as in macOS 12 Apple has changed parts of the Bluetooth stack from ker