Help needed with Kinivo BTD-400 Bluetooth USB Dongle on RPi4

I’ve installed the Kinivo BTD-400 on my up to date hassos Raspberry Pi4 but it doesn’t seem to be working as expected.

I’m getting the following logs:

Logger: homeassistant.components.bluetooth.scanner
Source: components/bluetooth/scanner.py:336
Integration: Bluetooth (documentation, issues)
First occurred: 07:31:00 (151 occurrences)
Last logged: 17:26:03

hci0 (1A:2B:3C:4D:5E:6F): Error stopping scanner: [org.bluez.Error.Failed] No discovery started
hci0 (1A:2B:3C:4D:5E:6F): Error stopping scanner: [org.bluez.Error.NotReady] Resource Not Ready

And the corresponding host logs:

Jan 18 17:08:08 homeassistant kernel: usb 1-1.2.1: new full-speed USB device number 35 using xhci_hcd
Jan 18 17:08:08 homeassistant kernel: usb 1-1.2.1: New USB device found, idVendor=0a5c, idProduct=21e8, bcdDevice= 1.12
Jan 18 17:08:08 homeassistant kernel: usb 1-1.2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jan 18 17:08:08 homeassistant kernel: usb 1-1.2.1: Product: BCM20702A0
Jan 18 17:08:08 homeassistant kernel: usb 1-1.2.1: Manufacturer: Broadcom Corp
Jan 18 17:08:08 homeassistant kernel: usb 1-1.2.1: SerialNumber: 1A2B3C4D5E6F
Jan 18 17:08:08 homeassistant systemd[1]: Reached target Bluetooth Support.
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM: chip id 63
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM: features 0x07
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM20702A
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM20702A1 (001.002.014) build 0000
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM: firmware Patch file not found, tried:
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM: 'brcm/BCM20702A1.raspberrypi,4-model-b.hcd'
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM: 'brcm/BCM20702A1-0a5c-21e8.hcd'
Jan 18 17:08:08 homeassistant kernel: Bluetooth: hci0: BCM: 'brcm/BCM-0a5c-21e8.hcd'
Jan 18 17:08:08 homeassistant bluetoothd[388]: Battery Provider Manager created
Jan 18 17:08:08 homeassistant bluetoothd[388]: Adv Monitor Manager created with supported features:0x00000000, enabled features:0x00000000, max number of supported monitors:32, max number of supported patterns:16
Jan 18 17:08:08 homeassistant bluetoothd[388]: Endpoint registered: sender=:1.36 path=/MediaEndpoint/A2DPSink/sbc
Jan 18 17:08:08 homeassistant bluetoothd[388]: Endpoint registered: sender=:1.36 path=/MediaEndpoint/A2DPSource/sbc
Jan 18 17:12:19 homeassistant kernel: usb 1-1.2.1: USB disconnect, device number 35
Jan 18 17:12:19 homeassistant bluetoothd[388]: Endpoint unregistered: sender=:1.36 path=/MediaEndpoint/A2DPSink/sbc
Jan 18 17:12:19 homeassistant bluetoothd[388]: Endpoint unregistered: sender=:1.36 path=/MediaEndpoint/A2DPSource/sbc
Jan 18 17:12:19 homeassistant bluetoothd[388]: Destroy Adv Monitor Manager
Jan 18 17:12:19 homeassistant bluetoothd[388]: Battery Provider Manager destroyed
Jan 18 17:12:19 homeassistant systemd[1]: Stopped target Bluetooth Support.
Jan 18 17:12:19 homeassistant kernel: usb 1-1.2.1: new full-speed USB device number 36 using xhci_hcd
Jan 18 17:12:20 homeassistant kernel: usb 1-1.2.1: New USB device found, idVendor=0a5c, idProduct=21e8, bcdDevice= 1.12
Jan 18 17:12:20 homeassistant kernel: usb 1-1.2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jan 18 17:12:20 homeassistant kernel: usb 1-1.2.1: Product: BCM20702A0
Jan 18 17:12:20 homeassistant kernel: usb 1-1.2.1: Manufacturer: Broadcom Corp
Jan 18 17:12:20 homeassistant kernel: usb 1-1.2.1: SerialNumber: 1A2B3C4D5E6F
Jan 18 17:12:20 homeassistant systemd[1]: Reached target Bluetooth Support.
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM: chip id 63
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM: features 0x07
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM20702A
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM20702A1 (001.002.014) build 0000
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM: firmware Patch file not found, tried:
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM: 'brcm/BCM20702A1.raspberrypi,4-model-b.hcd'
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM: 'brcm/BCM20702A1-0a5c-21e8.hcd'
Jan 18 17:12:20 homeassistant kernel: Bluetooth: hci0: BCM: 'brcm/BCM-0a5c-21e8.hcd'
Jan 18 17:12:20 homeassistant bluetoothd[388]: Battery Provider Manager created
Jan 18 17:12:20 homeassistant bluetoothd[388]: Adv Monitor Manager created with supported features:0x00000000, enabled features:0x00000000, max number of supported monitors:32, max number of supported patterns:16
Jan 18 17:12:20 homeassistant bluetoothd[388]: Endpoint registered: sender=:1.36 path=/MediaEndpoint/A2DPSink/sbc
Jan 18 17:12:20 homeassistant bluetoothd[388]: Endpoint registered: sender=:1.36 path=/MediaEndpoint/A2DPSource/sbc

I purchased this particular device as I thought it would be compatible out of the box but it seems not to be the case? I’m happy to update firmware / drivers myself but I don’t know how (and any updates need to survive a system restart / hardware reboot).

If anyone has had a similar experience or could point me in the right direction I would much appreciate it.

Thanks in advance

RPi4 running:

Home Assistant 2023.1.5
Supervisor 2022.12.1
Operating System 9.4
Frontend 20230110.0 - latest