I am using AMD Ryzen 5 5600G after upgraded from 15.3 to 15.4 sound does come
out of HDMI. It seems snd_hda_codec_hdmi not being loaded during boot process.
I had to run YaST to add kernel module "AMD ACP Renoir PCI driver", the add
process failed load to the kernel module but pasystray manage find "New sink
Renoir Radon High Definition Audio Controller Digital Stereo (HDMI)" and load
snd_hda_codec_hdmi.

My Hardware:

0a:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc.
[AMD/ATI] Cezanne [1002:1638] (rev c9) (prog-if 00 [VGA controller])
        Subsystem: Gigabyte Technology Co., Ltd Device [1458:d000]
        Flags: bus master, fast devsel, latency 0, IRQ 30
        Memory at ffe0000000 (64-bit, prefetchable) [size=256M]
        Memory at fff0000000 (64-bit, prefetchable) [size=2M]
        I/O ports at e000 [size=256]
        Memory at fca00000 (32-bit, non-prefetchable) [size=512K]
        Capabilities: [48] Vendor Specific Information: Len=08 <?>
        Capabilities: [50] Power Management version 3
        Capabilities: [64] Express Legacy Endpoint, MSI 00
        Capabilities: [a0] MSI: Enable- Count=1/4 Maskable- 64bit+
        Capabilities: [c0] MSI-X: Enable+ Count=4 Masked-
        Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010
<?>
        Capabilities: [270] #19
        Capabilities: [2a0] Access Control Services
        Capabilities: [2b0] Address Translation Service (ATS)
        Capabilities: [2c0] Page Request Interface (PRI)
        Capabilities: [2d0] Process Address Space ID (PASID)
        Capabilities: [400] #25
        Capabilities: [410] #26
        Capabilities: [440] #27
        Kernel driver in use: amdgpu
        Kernel modules: amdgpu

0a:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Renoir
Radeon High Definition Audio Controller [1002:1637]
        Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Renoir Radeon High
Definition Audio Controller [1002:1637]
        Flags: bus master, fast devsel, latency 0, IRQ 41
        Memory at fca80000 (32-bit, non-prefetchable) [size=16K]
        Capabilities: [48] Vendor Specific Information: Len=08 <?>
        Capabilities: [50] Power Management version 3
        Capabilities: [64] Express Legacy Endpoint, MSI 00
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010
<?>
        Capabilities: [2a0] Access Control Services
        Kernel driver in use: snd_hda_intel
        Kernel modules: snd_hda_intel

OS version:

5.14.21-150400.22-default

Sound modules after boot:

snd_hda_intel          57344  0
snd_intel_dspcfg       28672  1 snd_hda_intel
snd_intel_sdw_acpi     20480  1 snd_intel_dspcfg
snd_hda_codec         172032  1 snd_hda_intel
snd_hwdep              16384  1 snd_hda_codec
snd_hda_core          106496  2 snd_hda_intel,snd_hda_codec
snd_pcm               172032  3 snd_hda_intel,snd_hda_codec,snd_hda_core
snd_timer              40960  1 snd_pcm
snd                   114688  5
snd_hwdep,snd_hda_intel,snd_hda_codec,snd_timer,snd_pcm
soundcore              16384  1 snd


Sound modules after add "AMD ACP Renoir PCI driver"

snd_hda_codec_hdmi     73728  1
snd_hda_intel          57344  4
snd_intel_dspcfg       28672  1 snd_hda_intel
snd_intel_sdw_acpi     20480  1 snd_intel_dspcfg
snd_hda_codec         172032  2 snd_hda_codec_hdmi,snd_hda_intel
snd_hda_core          106496  3 snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec
snd_hwdep              16384  1 snd_hda_codec
snd_pcm               172032  5
snd_hda_codec_hdmi,snd_hda_intel,snd_hda_codec,snd_hda_core
snd_timer              40960  1 snd_pcm
snd                   114688  13
snd_hda_codec_hdmi,snd_hwdep,snd_hda_intel,snd_hda_codec,snd_timer,snd_pcm
soundcore              16384  1 snd

Best Regards