HDMI sound output option not shown in Horus

Question

I've looked at (and tried) several solutions in order to fix this problem, but unsuccessfully. Most of the issues I've read about have to do with older releases of eOS, so that some of the known [as yet] unsupported hardware would have been addressed in Horus (Ubuntu 20.04), but it appears that they have not. Following is a list of several outputs containing details about my configuration. Thank you!

xy@eOS-ASRock-VisionX-420D:~$ lspci
00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor DRAM Controller (rev 06)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller (rev 06)
00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05)
00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-V (rev 05)
00:1a.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5)
00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d5)
00:1c.4 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #5 (rev d5)
00:1d.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation HM87 Express LPC Controller (rev 05)
00:1f.2 IDE interface: Intel Corporation 8 Series Chipset Family 4-port SATA Controller 1 [IDE mode] - Mobile (rev 05)
00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05)
00:1f.5 IDE interface: Intel Corporation 8 Series/C220 Series Chipset Family 2-port SATA Controller 2 [IDE mode] (rev 05)
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Venus XT [Radeon HD 8870M / R9 M270X/M370X]
01:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Oland/Hainan/Cape Verde/Pitcairn HDMI Audio [Radeon HD 7000 Series]
03:00.0 Network controller: Broadcom Inc. and subsidiaries BCM4352 802.11ac Wireless Network Adapter (rev 03)
04:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS5229 PCI Express Card Reader (rev 01)

xy@eOS-ASRock-VisionX-420D:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: PCH [HDA Intel PCH], device 0: ALC1150 Analog [ALC1150 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: PCH [HDA Intel PCH], device 1: ALC1150 Digital [ALC1150 Digital]
  Subdevices: 0/1
  Subdevice #0: subdevice #0

xy@eOS-ASRock-VisionX-420D:~$ dmesg | grep -i snd
dmesg: read kernel buffer failed: Operation not permitted
xy@eOS-ASRock-VisionX-420D⍨$

xy@eOS-ASRock-VisionX-420D:~$ inxi -Fxz
System:
  Kernel: 5.19.0-35-generic x86_64 bits: 64 compiler: N/A Desktop: Pantheon
    Distro: elementary OS 7 Horus
Machine:
  Type: Desktop Mobo: ASRock model: HM87-MXM serial: <superuser required>
    BIOS: American Megatrends v: P2.10 date: 11/26/2014
Battery:
  Device-1: apple_mfi_fastcharge model: N/A charge: N/A status: N/A
CPU:
  Info: dual core model: Intel Core i5-4200M bits: 64 type: MT MCP
    arch: Haswell rev: 3 cache: L1: 128 KiB L2: 512 KiB L3: 3 MiB
  Speed (MHz): avg: 3031 high: 3071 min/max: 800/3100 cores: 1: 3071
    2: 2998 3: 3056 4: 2999 bogomips: 19994
  Flags: avx avx2 ht lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx
Graphics:
  Device-1: AMD Venus XT [Radeon HD 8870M / R9 M270X/M370X] driver: radeon
    v: kernel bus-ID: 01:00.0
  Display: x11 server: X.Org v: 1.21.1.3 driver: X: loaded: ati,radeon
    unloaded: fbdev,modesetting,vesa gpu: radeon resolution: 1680x1050~60Hz
  OpenGL: renderer: VERDE ( LLVM 15.0.6 DRM 2.50 5.19.0-35-generic)
    v: 4.5 Mesa 22.2.5 direct render: Yes
Audio:
  Device-1: Intel 8 Series/C220 Series High Definition Audio vendor: ASRock
    driver: snd_hda_intel v: kernel bus-ID: 00:1b.0
  Device-2: AMD Oland/Hainan/Cape Verde/Pitcairn HDMI Audio [Radeon HD 7000
  Series]
    driver: snd_hda_intel v: kernel bus-ID: 01:00.1
  Sound Server-1: ALSA v: k5.19.0-35-generic running: yes
  Sound Server-2: PulseAudio v: 15.99.1 running: yes
  Sound Server-3: PipeWire v: 0.3.48 running: yes
Network:
  Device-1: Intel Ethernet I217-V vendor: ASRock driver: e1000e v: kernel
    port: f020 bus-ID: 00:19.0
  IF: enp0s25 state: down mac: <filter>
  Device-2: Broadcom BCM4352 802.11ac Wireless Network Adapter
    vendor: AzureWave driver: bcma-pci-bridge v: N/A bus-ID: 03:00.0
  IF-ID-1: enx82045f395f21 state: up speed: N/A duplex: N/A mac: <filter>
Bluetooth:
  Device-1: IMC Networks BCM20702A0 type: USB driver: btusb v: 0.8
    bus-ID: 3-14:4
  Report: hciconfig ID: hci0 rfk-id: 0 state: up address: <filter>
    bt-v: 2.1 lmp-v: 4.0
Drives:
  Local Storage: total: 5.84 TiB used: 10.8 GiB (0.2%)
  ID-1: /dev/sda vendor: Western Digital model: WD1600BEVT-75ZCT2
    size: 149.05 GiB
  ID-2: /dev/sdb vendor: Smart Modular Tech. model: SH00M256GB
    size: 238.47 GiB
  ID-3: /dev/sdc type: USB vendor: Innostor model: Ext. HDD size: 5.46 TiB
Partition:
  ID-1: / size: 228.72 GiB used: 10.53 GiB (4.6%) fs: ext4 dev: /dev/dm-0
    mapped: data-root
  ID-2: /boot size: 1.16 GiB used: 274.9 MiB (23.2%) fs: ext4
    dev: /dev/sdb1
Swap:
  ID-1: swap-1 type: partition size: 3.82 GiB used: 0 KiB (0.0%)
    dev: /dev/dm-2 mapped: cryptswap
Sensors:
  System Temperatures: cpu: 53.0 C mobo: 27.8 C gpu: radeon temp: 62.0 C
  Fan Speeds (RPM): N/A
Info:
  Processes: 289 Uptime: 3m Memory: 7.68 GiB used: 1.7 GiB (22.1%)
  Init: systemd runlevel: 5 Compilers: gcc: N/A Packages: 1637 Shell: Bash
  v: 5.1.16 inxi: 3.3.13