After lots of research, trial, and errors, I managed to get the audio fully working on the ASUS Zenbook.
Open terminal and input these commands to test to see if the fix works. A restart will undo the commands.
$ sudo hda-verb /dev/snd/hwC0D0 0x20 0x500 0x1b
$ sudo hda-verb /dev/snd/hwC0D0 0x20 0x477 0x4a4b
$ sudo hda-verb /dev/snd/hwC0D0 0x20 0x500 0xf
$ sudo hda-verb /dev/snd/hwC0D0 0x20 0x477 0x74
If the commands work, you can create an SH script that runs on boot. Below is the SH script.
#!/bin/bash
sudo hda-verb /dev/snd/hwC0D0 0x20 0x500 0x1b
sudo hda-verb /dev/snd/hwC0D0 0x20 0x477 0x4a4b
sudo hda-verb /dev/snd/hwC0D0 0x20 0x500 0xf
sudo hda-verb /dev/snd/hwC0D0 0x20 0x477 0x74