I removed Wireplumber and installed Pipewire Session Manager. Sound is IN, desktop lags are Out! Miracle! Still keeping my fingers crossed.
THANK YOU ALL FOR THE HELP AND SUPPORT! 
Just wanna say thank you because this worked for me as well. No HDMI sound from my RX 470 and removing Wireplumber and installing Pipewire Session Manager then restarting the machine got HDMI sound working. Devices now appear and I can set them.
I was able to get it working without removing wireplumber by sending a bunch of verbs. See the fix here No sound on Razer Blade 18 speakers on fresh install - #4 by Nwhy
I had the same issue. I solved it with AI.
I backed up the modprobe folder:
sudo cp -r /etc/modprobe.d ~/modprobe-backup2-$(date +%Y%m%d)
Then installed alsa firmware:
sudo pacman -S alsa-firmware
I made a new configuration file to a) change mod load order to prevent timeouts and b) priorize Intel before HDA Nvidia.
sudo nano /etc/modprobe.d/50-sof-zbook.conf
with
**# Fix SOF Probe-Timeout auf HP ZBook 15 G6: Lade Realtek-Codec vor SOF-DSP
softdep snd_sof_pci_intel_cnl pre: snd_hda_codec_realtek
softdep snd_sof_intel_hda_common pre: snd_hda_codec_realtek
SOF-Quirk für HP ZBook 15 G6 (Cannon Lake ALC285): Force SOF-DSP-Mode
options snd-intel-dspcfg dsp_driver=1 index=0
Depriorisiere Nvidia HDA (HDMI-only), damit Intel Card 0 wird
options snd_hda_intel index=-2,0 pciid=10de:10fa index=-2 # Nvidia zu -2 (low), Intel zu 0**
Then everything is running fine again. You will have both Soundcards selectable. Perfect solution to me.