HDMI sound not working

[Ton Hofhuis]

Running Ubuntu 23.04 with all the latest patches on Dell XPS 15 9510/Nvidia 3050Ti via Thunderbolt 4 cable attached to a DELL WB22TB4 dockingstation via Displayport 2.0 cable to an Asus 4K monitor with an audio out to a surround set.
The sound via HDMI was working great when running 22.10, but works rarely on 23.04 (I haven't figured out which set-up it always does work). nVidia driver = 525.105.17

More questions on <email address hidden> or via MM @ton211

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: alsa-base 1.0.25+dfsg-0ubuntu7
ProcVersionSignature: Ubuntu 6.2.0-20.20-generic 6.2.6
Uname: Linux 6.2.0-20-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair nvidia_modeset nvidia
ApportVersion: 2.26.1-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: ton 5180 F.... wireplumber
 /dev/snd/controlC1: ton 5180 F.... wireplumber
 /dev/snd/pcmC1D0c: ton 5176 F...m pipewire
 /dev/snd/seq: ton 5176 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Fri May 12 16:06:40 2023
InstallationDate: Installed on 2023-02-02 (98 days ago)
InstallationMedia: Ubuntu 22.10 "Kinetic Kudu" - Release amd64 (20221020)
PackageArchitecture: all
SourcePackage: alsa-driver
Symptom: audio
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/10/2023
dmi.bios.release: 1.19
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.19.0
dmi.board.name: 01V4T3
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.19.0:bd03/10/2023:br1.19:svnDellInc.:pnXPS159510:pvr:rvnDellInc.:rn01V4T3:rvrA00:cvnDellInc.:ct10:cvr:sku0A61:
dmi.product.family: XPS
dmi.product.name: XPS 15 9510
dmi.product.sku: 0A61
dmi.sys.vendor: Dell Inc.