External Headset with 3.5mm TRS connector has no sound with SOF on ALC256 chipset

[marralesfios]

My MSI Cyborg 15 A13VE laptop is running Arch Linux with kernel Linux 6.16.10-arch1-1. The internal DMIC and speaker, as well as audio playback through the headset are fine, but when the headset is plugged in, its microphone is not detected. (the built-in DMIC remains active)

Output of sudo dmesg | grep snd:

[    5.470944] snd_hda_intel 0000:00:1f.3: Digital mics found on Skylake+ platform, using SOF driver
[    5.470989] snd_hda_intel 0000:01:00.1: enabling device (0000 -> 0002)
[    5.471050] snd_hda_intel 0000:01:00.1: Disabling MSI
[    5.471055] snd_hda_intel 0000:01:00.1: Handle vga_switcheroo audio client
[    5.812824] snd_hda_codec_realtek ehdaudio0D0: autoconfig for ALC256: line_outs=1 (0x14/0x0/0x0/0x0/0x0) type:speaker
[    5.812830] snd_hda_codec_realtek ehdaudio0D0:    speaker_outs=0 (0x0/0x0/0x0/0x0/0x0)
[    5.812832] snd_hda_codec_realtek ehdaudio0D0:    hp_outs=1 (0x21/0x0/0x0/0x0/0x0)
[    5.812834] snd_hda_codec_realtek ehdaudio0D0:    mono: mono_out=0x0
[    5.812836] snd_hda_codec_realtek ehdaudio0D0:    inputs:
[    5.812838] snd_hda_codec_realtek ehdaudio0D0:      Mic=0x19

Output of sudo dmesg | grep sof:

[    0.041088] software IO TLB: area num 16.
[    0.594298] PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
[    0.594299] software IO TLB: mapped [mem 0x0000000031d5c000-0x0000000035d5c000] (64MB)
[    0.741644] integrity: Loaded X.509 cert 'Microsoft Windows Production PCA 2011: a92902398e16c49778cd90f99e4f9ae17c55af53'
[    0.741657] integrity: Loaded X.509 cert 'Microsoft Corporation UEFI CA 2011: 13adbf4309bd82709c8cd54f316ed522988a1bd4'
[    0.741667] integrity: Loaded X.509 cert 'Microsoft Corporation: Windows UEFI CA 2023: aefc5fbbbe055d8f8daa585473499417ab5a5272'
[    0.741678] integrity: Loaded X.509 cert 'Microsoft UEFI CA 2023: 81aa6b3244c935bce0d6628af39827421e32497d'
[    5.643686] sof-audio-pci-intel-tgl 0000:00:1f.3: enabling device (0000 -> 0002)
[    5.643815] sof-audio-pci-intel-tgl 0000:00:1f.3: DSP detected with PCI class/subclass/prog-if 0x040100
[    5.643849] sof-audio-pci-intel-tgl 0000:00:1f.3: bound 0000:00:02.0 (ops intel_audio_component_bind_ops [i915])
[    5.650226] sof-audio-pci-intel-tgl 0000:00:1f.3: use msi interrupt mode
[    5.681731] sof-audio-pci-intel-tgl 0000:00:1f.3: hda codecs found, mask 5
[    5.681736] sof-audio-pci-intel-tgl 0000:00:1f.3: using HDA machine driver skl_hda_dsp_generic now
[    5.681739] sof-audio-pci-intel-tgl 0000:00:1f.3: NHLT device BT(0) detected, ssp_mask 0x4
[    5.681741] sof-audio-pci-intel-tgl 0000:00:1f.3: BT link detected in NHLT tables: 0x4
[    5.681743] sof-audio-pci-intel-tgl 0000:00:1f.3: DMICs detected in NHLT tables: 2
[    5.685477] sof-audio-pci-intel-tgl 0000:00:1f.3: Firmware paths/files for ipc type 0:
[    5.685481] sof-audio-pci-intel-tgl 0000:00:1f.3:  Firmware file:     intel/sof/sof-rpl.ri
[    5.685482] sof-audio-pci-intel-tgl 0000:00:1f.3:  Topology file:     intel/sof-tplg/sof-hda-generic-2ch.tplg
[    5.686159] sof-audio-pci-intel-tgl 0000:00:1f.3: Firmware info: version 2:2:0-57864
[    5.686162] sof-audio-pci-intel-tgl 0000:00:1f.3: Firmware: ABI 3:22:1 Kernel ABI 3:23:1
[    5.778794] sof-audio-pci-intel-tgl 0000:00:1f.3: Firmware info: version 2:2:0-57864
[    5.778801] sof-audio-pci-intel-tgl 0000:00:1f.3: Firmware: ABI 3:22:1 Kernel ABI 3:23:1
[    5.796449] sof-audio-pci-intel-tgl 0000:00:1f.3: Topology: ABI 3:22:1 Kernel ABI 3:23:1
[    6.032094] input: sof-hda-dsp Mic as /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card1/input21
[    6.032160] input: sof-hda-dsp Headphone as /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card1/input22
[    6.032196] input: sof-hda-dsp HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card1/input23
[    6.032226] input: sof-hda-dsp HDMI/DP,pcm=4 as /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card1/input24
[    6.032262] input: sof-hda-dsp HDMI/DP,pcm=5 as /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card1/input25

Here is a screenshot of alsamixer, only detecting the dmic.