I have an Asus VivoBook S5402ZA laptop with a fresh installation of Ubuntu 22.04. The internal microphone works, but the headset microphone does not. If I connect the headset via a USB hub with a jack, it starts detecting the microphone. I have another ASUS ROG series laptop and when I plug in the headset it asks me which mode I want to use the headset or headphones in and the microphone works perfectly fine.
When I disable HD Audio support in the BIOS of this ROG laptop, it no longer prompts for the mode. On my Vivobook I have a similar setting in the BIOS, but switching it doesn't help. On Windows, when I plug in a headset, the HD Audio console pops up.
I've already tried to edit file /etc/modprobe.d/alsa-base.conf. I've been adding values from here https://www.kernel.org/doc/html/latest/sound/hd-audio/models.html (all, where I have seen headset, microphone or alc294 but it didn't help).
Headphones Stereo microphone is listed even if no headset is plugged in, and it doesn't work when I plug in a headset.
The same issue on Fedora and Manjaro.
Linux Asus-VivoBookS5402ZA 6.2.0-26-generic #26~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Thu Jul 13 16:27:29 UTC 2 x86_64 x86_64 x86_64 GNU/Linux
Codec: Realtek ALC294
AlsaLog: https://drive.google.com/file/d/1vkV2tlT1TfbKNF72DY8To7TpGo9G53ba/view?usp=sharing
I have an ASUS ROG mainboard. Under Linux, i also can't get the integrated USB HD Audio (ALC4080) to work. My solution was to buy an external sound card/amplifier/DAC. It's basically the same as with your USB hub.
Audio in Linux is hard sometimes, so keep in mind that when you're searching for an external sound card, it should explicitly have Linux support. Otherwise it won't work at all, maybe.
I got a Creative Sound BlasterX G6, which officially doesn't support linux. However, i had some luck and used alsamixer to change the input source.
You could also try checking alsamixer, sometimes channels are muted.