Are you using any power saving /power management tools? Maybe check the power settings in there and see if changing the power profile makes any difference.

Also:

• Check fwpudmgr for any firmware updates
• Try installing a more recent/optimised kernel, such as Xanmod (currently at 6.7.4). If you're getting Xanmod then get the x86-64-v3 variant
• Try a different distro, preferably one which has more recent packages. Fedora uBlue has an Asus variant which features an optimised kernel for Asus laptops, so it might be worth checking out.

I’ve had this before, try a different kernel, like an LTS, if that fixes it, there’s likely a kernel parameter somewhere to fiddle with.

I have a zenbook as well (not the same model) and I only had problems with Windows. When coming back from suspension it would be hot and the screen had like white fog on the edges. I tried to fix it but with no success. Frustrated with that I decided to give Linux a try and never had that problem again.

I assume you changed the ssd, I didn't know that was possible, I thought it was soldered to the motherboard. Is it possible you received a faulty drive from WD?

First, make sure your laptop bios is up to date. Updating should be a simple matter of downloading the naked bios file, put it on a fat32 stick, boot into bios and use the built-in flasher.

You could set up a winToUSB drive to run the WD firmware update tool.

Or, you could go through this. https://community.frame.work/t/western-digital-drive-update-guide-without-windows-wd-dashboard/20616