Bluetooth internal adapter issue

Configuration
1

Hello community,

Since my former homelab server crashed, I had to change it.
I managed to setup a new one and everything works just fine except : I can’t get the bluetooth internal adapter to work in Home Assistant.

I have Proxmox on my server, I do USB passthrough to the VM where I have HAOS. Everything is at the latest version possible right now (proxmox 9, HA 2026.4.3 …).

I can see on my HA with lsusb that it sees the BT adapter: Mediatek Inc. Wireless_Device

And I can see it fails to load the driver in dmesg:

bluetooth hci0: Direct firmware load for mediatek/mt7925/BT_RAM_CODE_MT7925_1_1_hdr.bin failed with error -2
Bluetooth: hci0: Failed to load firmware file (-2)
Bluetooth: hci0: Failed to set up formware (-2)

I have noticed the file was missing in /lib/firmware so I did put it there. Still not working.

I have found this link from 2023 stating a missing firmware file in HA but it was solved back then so I assume it should work ?!

I know I could stop trying and put an ESP BT Proxy, and will eventually if I can’t solve this but I would really prefer to have my server doing the job for the room it is in.

Any ideas ?

2

Can’t help you much because I’m not very familiar with bluetooth, but I did have a look at the OS code by following your link.

Looks like the MT7925 isn’t supported by the OS. If you look here, you’ll see that only the 7921 & 7922 are listed.

EDIT: Looks like someone requested support for it a couple of years ago Bluetooth Integration Does Not Recognise MediaTek MT7925 (Missing Support/Driver) · Issue #3676 · home-assistant/operating-system · GitHub

3

Thank you very much for taking some time to try and help me.
You are right, I digged so deep and for so long that I missed that the thread I refer to is not on the same version … Thanks !

Ok so now I have an answer, it seems it will be supported in kernel 6.13 and today in the HAOS 17 it is with kernel 6.12 so I guess I’ll plug an ESP BT Proxy and wait for HAOS to move on.

Again, thank you so much for your help !

4

@Nipal spotted this in the OS18.0 release notes & somehow managed to remember about your post. Looks like it's supported now!

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5

since update to OS18 I get

2026-06-21 13:05:25.929 WARNING (MainThread) [habluetooth.scanner] hci0 (00:A7:41:12:33:38): Error stopping scanner during active-window flip: [org.bluez.Error.DoesNotExist] Does Not Exist
2026-06-21 13:06:57.479 ERROR (MainThread) [habluetooth.scanner] hci0 (00:A7:41:12:33:38): Error stopping scanner
Traceback (most recent call last):
  File "src/habluetooth/scanner.py", line 987, in habluetooth.scanner.HaScanner._async_stop_scanner
  File "src/habluetooth/scanner.py", line 988, in habluetooth.scanner.HaScanner._async_stop_scanner
  File "/usr/local/lib/python3.14/site-packages/bleak/__init__.py", line 189, in stop
    await self._backend.stop()
  File "/usr/local/lib/python3.14/site-packages/bleak/backends/bluezdbus/scanner.py", line 144, in stop
    await stop()
  File "/usr/local/lib/python3.14/site-packages/bleak/backends/bluezdbus/manager.py", line 627, in stop
    assert_reply(reply)
    ~~~~~~~~~~~~^^^^^^^
  File "/usr/local/lib/python3.14/site-packages/bleak/backends/bluezdbus/utils.py", line 34, in assert_reply
    raise BleakDBusError(reply.error_name, reply.body)
bleak.exc.BleakDBusError: [org.bluez.Error.DoesNotExist] Does Not Exist

and my USB Bluetooth dongle (UGREEN Bluetooth 5.4 adapter) is no longer working

6

This thread has been solved & the topic had nothing to do with your issue. It might be better if you create your own thread & provide further details there.