[LE_WH-1000XM3, playback] Playback problem: BT headset only plays gnome-terminal's bell (Ctrl-G), any media/audio is still output via builtin intel audio

[Bernhard Gabler]

After today's update, no audio can be played via connected Bluetooth headset (Sony LE_WH-1000XM3). The sound setting offers internal speakers or wireless headset, but either way any media (RhythmBox, Web video, ...) plays through the internal speakers.

The notable exception is gnome-console's ping (played as output of a BELL character, like from hitting the backspace key on an empty bash command line, or from

  echo -e \\007

which does play through wireless headset (or internal speaker) as set by the sound setting.

Before today's update, the Bluetooth headset did play audio (yet not immediately upon connecting; for though the sound setting had switched to the external headset, any sound was still output to via internal speakers. But switching once to the internal speakers and back to the BT headset was a viable workaround to get sound out to the BT headset.)

From apt log:
Start-Date: 2020-06-18 17:19:14
Commandline: aptdaemon role='role-commit-packages' sender=':1.315'
Upgrade: bind9-dnsutils:amd64 (1:9.16.1-0ubuntu2.1, 1:9.16.1-0ubuntu2.2), alsa-ucm-conf:amd64 (1.2.2-1, 1.2.2-1ubuntu0.1), bind9-host:amd64 (1:9.16.1-0ubuntu2.1, 1:9.16.1-0ubuntu2.2), dnsutils:amd64 (1:9.16.1-0ubuntu2.1, 1:9.16.1-0ubuntu2.2), initramfs-tools-bin:amd64 (0.136ubuntu6, 0.136ubuntu6.1), busybox-static:amd64 (1:1.30.1-4ubuntu6, 1:1.30.1-4ubuntu6.1), bind9-libs:amd64 (1:9.16.1-0ubuntu2.1, 1:9.16.1-0ubuntu2.2), initramfs-tools-core:amd64 (0.136ubuntu6, 0.136ubuntu6.1), initramfs-tools:amd64 (0.136ubuntu6, 0.136ubuntu6.1), gnome-shell-extension-ubuntu-dock:amd64 (67ubuntu20.04.5, 68ubuntu1~20.04.1), busybox-initramfs:amd64 (1:1.30.1-4ubuntu6, 1:1.30.1-4ubuntu6.1)
Remove: linux-image-5.3.0-55-generic:amd64 (5.3.0-55.49), linux-modules-extra-5.3.0-55-generic:amd64 (5.3.0-55.49), linux-headers-5.3.0-55-generic:amd64 (5.3.0-55.49), linux-modules-5.3.0-55-generic:amd64 (5.3.0-55.49), linux-headers-5.3.0-55:amd64 (5.3.0-55.49)
End-Date: 2020-06-18 17:20:14

Could the issue be caused by one of these packages?
  alsa-ucm-conf:amd64 (1.2.2-1, 1.2.2-1ubuntu0.1)
  gnome-shell-extension-ubuntu-dock:amd64 (67ubuntu20.04.5, 68ubuntu1~20.04.1)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: alsa-base 1.0.25+dfsg-0ubuntu5
ProcVersionSignature: Ubuntu 5.4.0-37.41-generic 5.4.41
Uname: Linux 5.4.0-37-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: bernhard 2078 F.... pulseaudio
 /dev/snd/pcmC0D0c: bernhard 2078 F...m pulseaudio
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Thu Jun 18 18:42:49 2020
EcryptfsInUse: Yes
InstallationDate: Installed on 2017-12-11 (919 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20171018)
PackageArchitecture: all
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: alsa-driver
Symptom: audio
Symptom_Card: LE_WH-1000XM3
Symptom_Type: Only some of outputs are working
Title: [LE_WH-1000XM3, playback] Playback problem
UpgradeStatus: Upgraded to focal on 2020-06-05 (13 days ago)
dmi.bios.date: 09/13/2017
dmi.bios.vendor: Insyde Corp.
dmi.bios.version: V1.01.
dmi.board.name: Woody_KL
dmi.board.vendor: KBL
dmi.board.version: V1.01.
dmi.chassis.type: 31
dmi.chassis.vendor: Acer
dmi.chassis.version: V1.01.
dmi.modalias: dmi:bvnInsydeCorp.:bvrV1.01.:bd09/13/2017:svnAcer:pnSpinSP513-52N:pvrV1.01.:rvnKBL:rnWoody_KL:rvrV1.01.:cvnAcer:ct31:cvrV1.01.:
dmi.product.family: Spin 5
dmi.product.name: Spin SP513-52N
dmi.product.sku: 0000000000000000
dmi.product.version: V1.01.
dmi.sys.vendor: Acer
mtime.conffile..etc.modprobe.d.alsa-base.conf: 2020-06-18T18:32:11.193118