Public bug reported:
Regression in BlueZ 5.72-0ubuntu5.5 prevents A2DP connection to Amazon
Echo Dot 4 (Clock) on Ubuntu 24.04.4 LTS
Regression confirmed through package downgrade testing: downgrading the
Ubuntu BlueZ packages from version 5.72-0ubuntu5.5 to 5.72-0ubuntu5
immediately restores Bluetooth A2DP functionality for an Amazon Echo Dot
4 (Clock) without any other system changes. The behavior is 100%
reproducible.
Summary
After upgrading the Ubuntu BlueZ packages from version 5.72-0ubuntu5 to
5.72-0ubuntu5.5, my Amazon Echo Dot 4 (Clock) could no longer be used as
a Bluetooth speaker.
The device is successfully discovered and paired, Bluetooth services are
resolved correctly, but the A2DP connection fails immediately afterward
and the device disconnects before becoming available as an audio output.
Downgrading only the BlueZ packages restores normal operation
immediately.
Environment
Operating System:
Ubuntu 24.04.4 LTS
Bluetooth packages (working):
bluez 5.72-0ubuntu5
bluez-cups 5.72-0ubuntu5
bluez-obexd 5.72-0ubuntu5
Bluetooth packages (failing):
bluez 5.72-0ubuntu5.5
bluez-cups 5.72-0ubuntu5.5
bluez-obexd 5.72-0ubuntu5.5
Audio stack:
PipeWire 1.0.5
WirePlumber 0.4.17
Hardware:
Motherboard: ASUS ROG STRIX Z790-H
Bluetooth device: Amazon Echo Dot 4 (Clock)
Expected behavior
The Echo Dot should connect successfully as a Bluetooth speaker (A2DP
sink), appear as an available audio output device, and allow audio
playback.
Actual behavior
The device is discovered successfully.
The device pairs successfully.
The Bluetooth connection starts successfully.
Services are resolved successfully.
The A2DP connection immediately fails.
The connection is canceled.
The device disconnects before becoming available as an audio output.
No audio can be played through the Echo Dot.
bluetoothctl output
[NEW] Device 50:D4:5C:A2:9B:78 Echo Dot-5N3
connect 50:D4:5C:A2:9B:78
Attempting to connect to 50:D4:5C:A2:9B:78
[CHG] Device 50:D4:5C:A2:9B:78 Connected: yes
[CHG] Device 50:D4:5C:A2:9B:78 ServicesResolved: yes
[CHG] Device 50:D4:5C:A2:9B:78 ServicesResolved: no
Failed to connect: org.bluez.Error.Failed br-connection-canceled
[CHG] Device 50:D4:5C:A2:9B:78 Connected: no
bluetoothd log
profiles/audio/avdtp.c:avdtp_connect_cb() connect to 50:D4:5C:A2:9B:78:
Function not implemented (38)
src/service.c:btd_service_connect() a2dp-source profile connect failed
for 50:D4:5C:A2:9B:78: Device or resource busy
Troubleshooting performed
Before identifying the regression, I performed the following
troubleshooting steps:
* Removed the Echo Dot from Ubuntu Bluetooth settings.
* Removed the Ubuntu computer from the Alexa Bluetooth device list.
* Factory reset the Echo Dot.
* Re-paired the device from scratch.
* Deleted the BlueZ pairing cache under /var/lib/bluetooth.
* Restarted the Bluetooth service.
* Verified that PipeWire was running correctly.
* Verified that WirePlumber was running correctly.
* Verified that the PipeWire Bluetooth plugin (libspa-0.2-bluetooth) was
installed.
* Removed user PipeWire and WirePlumber configuration directories to eliminate
possible configuration issues.
* Verified that other Bluetooth devices connect and function normally under
Ubuntu.
* Verified that the same Echo Dot connects and works correctly under Windows on
the same physical computer.
None of the above resolved the issue.
Package downgrade verification
The only change required to restore functionality was downgrading these
packages:
bluez
bluez-cups
bluez-obexd
from version:
5.72-0ubuntu5.5
to version:
5.72-0ubuntu5
No other packages, services or configuration files were modified as part
of the successful fix.
Immediately after the downgrade:
* The Echo Dot connected successfully.
* The device became available as an audio output.
* Audio playback worked normally.
Additional observations
The issue does not appear to be related to Bluetooth hardware because:
* The same Echo Dot works correctly on Windows using the same computer and
Bluetooth adapter.
* Other Bluetooth audio devices continue to work correctly under Ubuntu.
* The issue is fully resolved by reverting only the Ubuntu BlueZ packages to
the previous package revision.
Regression summary
Last known working package version:
bluez 5.72-0ubuntu5
First known failing package version:
bluez 5.72-0ubuntu5.5
Affected functionality:
Bluetooth A2DP audio connection to Amazon Echo Dot 4 (Clock)
Observed symptoms:
* Successful pairing.
* Successful Bluetooth service discovery.
* AVDTP connection failure.
* Connection canceled before the audio endpoint becomes available.
Based on the reproducible behavior and the successful package downgrade,
this strongly suggests a regression introduced between Ubuntu BlueZ
package revisions 5.72-0ubuntu5 and 5.72-0ubuntu5.5.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: bluez 5.72-0ubuntu5
ProcVersionSignature: Ubuntu 6.17.0-35.35~24.04.1-generic 6.17.13
Uname: Linux 6.17.0-35-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.28.1-0ubuntu3.8
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Jul 6 19:45:43 2026
InstallationDate: Installed on 2024-09-14 (661 days ago)
InstallationMedia: Ubuntu 24.04.1 LTS "Noble Numbat" - Release amd64
(20240827.1)
InterestingModules: btusb rfcomm bnep bluetooth
MachineType: ASUS System Product Name
ProcEnviron:
LANG=pt_BR.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.17.0-35-generic
root=UUID=19dad76a-6513-40ad-93af-6d91319eaa44 ro quiet splash vt.handoff=7
SourcePackage: bluez
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/07/2025
dmi.bios.release: 30.1
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 3001
dmi.board.asset.tag: Default string
dmi.board.name: ROG STRIX Z790-H GAMING WIFI
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev 1.xx
dmi.chassis.asset.tag: Default string
dmi.chassis.type: 3
dmi.chassis.vendor: Default string
dmi.chassis.version: Default string
dmi.modalias:
dmi:bvnAmericanMegatrendsInc.:bvr3001:bd03/07/2025:br30.1:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnROGSTRIXZ790-HGAMINGWIFI:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU:
dmi.product.family: To be filled by O.E.M.
dmi.product.name: System Product Name
dmi.product.sku: SKU
dmi.product.version: System Version
dmi.sys.vendor: ASUS
hciconfig:
hci0: Type: Primary Bus: USB
BD Address: B0:DC:EF:29:EC:BB ACL MTU: 1021:4 SCO MTU: 96:6
UP RUNNING
RX bytes:273448 acl:80 sco:0 events:35001 errors:0
TX bytes:30570717 acl:33109 sco:0 commands:1442 errors:0
modified.conffile..etc.bluetooth.input.conf: [modified]
modified.conffile..etc.bluetooth.main.conf: [modified]
mtime.conffile..etc.bluetooth.input.conf: 2026-07-06T18:02:23.378412
mtime.conffile..etc.bluetooth.main.conf: 2026-07-06T18:02:23.372469
rfkill:
6: hci0: Bluetooth
Soft blocked: no
Hard blocked: no
** Affects: bluez (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble
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https://bugs.launchpad.net/bugs/2159829
Title:
Regression in BlueZ 5.72-0ubuntu5.5 prevents A2DP connection to Amazon
Echo Dot 4 on Ubuntu 24.04.4 LTS
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