The new Pi 400 has a slightly different Wifi/BT chip to the Pi4. Whilst wifi works happily, Bluetooth fails to operate. This doesn't appear to be an issue with either the firmware (the latest versions from upstream Raspbian have been tried), or the kernel (a known-good raspi kernel has been tested under Ubuntu), but with Bluez itself. Specifically, tracing the initialization with btmon on Raspbian and Ubuntu, the stack consistently fails when attempting to "Set Default PHY" on the latter. Curiously, under Ubuntu the adapter also appears to lack a MAC address.
The new Pi 400 has a slightly different Wifi/BT chip to the Pi4. Whilst wifi works happily, Bluetooth fails to operate. This doesn't appear to be an issue with either the firmware (the latest versions from upstream Raspbian have been tried), or the kernel (a known-good raspi kernel has been tested under Ubuntu), but with Bluez itself. Specifically, tracing the initialization with btmon on Raspbian and Ubuntu, the stack consistently fails when attempting to "Set Default PHY" on the latter. Curiously, under Ubuntu the adapter also appears to lack a MAC address.