The problem is that the internal digital microphone array (Intel SST) was added to laptops for Cortana support and were not supported on Linux. sof-firmware support was added to Linux kernel earlier this year, but most laptops did not have any working audio. The workaround for most users was to disable the digital microphone to continue using the rest of the the audio system until the bugs were patched
Your system can detect the digital microphone
Digital mics found on Skylake+ platform, using SST driver
but it cannot load the driver correctly, so all the onboard audio fails to be initialised
to get a working system you need the latest version of PulseAudio that has the patches for sof-firmware
A new version of PulseAudio (v13.99) was included in [Testing Update] 2020-10-16 so installing pulseaudio-git from AUR is no longer needed
You can either switch to testing branch now to get packages needed for working audio
Switching Branches - Manjaro Wiki
or else wait for a week or two for new packages to be released in a stable update