Then at this point, I can only suggest you either try Reinstalling Zorin OS or check the Mainline kernel.
Zorin OS should come with the HWE Kernel... It is built off of Ubuntu as a base just like Mint and many other distros. So if "every other Linux" runs well, I would suspect a corruption occurred during the OS installation. If this is a fresh install, then a reinstall may be painless.
Luckily I just installed it today and have mostly nothing installed yet so... I'll update you in a bit.
And back. Did not see the gear icon on login. Currently doing updates.
Hmmm... is this Zorin OS LITE that you are installing?
Nope, Core 15.3. Just finished updates and there are no changes.
And... you ARE clicking the Gear Icon, right?
In the log in screen? There is no gear icon to click.
This is an Ubuntu screen as I cannot easily find a Zorin one- but the GDM3 layout is the same:
Yeah, it's not there.
You may try reinstalling GDM3, but I doubt that is the issue as you just did two fresh installations of the system. Other than that, I can think of no reason that the desktop environment selection icon could be missing.
On my copy of Zorin Core, the icon shows the option for "Zorin on Wayland".
I attempted the /etc/gdm3/custom.conf edit and there was no change, and also checked uname -a and there were no changes there. It's possible switching to Wayland won't actually solve my issues (slow UI, no animations, screen tearing
I could try installing Lite but I'm pretty sure my laptop should be able to handle Core without issue.
What Graphics card does your notebook have?
Radeon RX Vega 6 integrated (CPU is Ryzen 5 4500u)
You might try upping the graphics drivers;
sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt update
sudo apt full-upgrade
Then reboot and test to see if you UI is properly responsive.
After some tests that didn't seem to help much, for example YouTube does not like to play 1080p video and is just slow overall. Still bad screen tearing and no animations. (Animations are enabled)
Should I attempt to install Zorin OS Lite?
Because of the ryzen 5 cpu i suspect you're hardware falls in the grey range of supported that resulted from a gap due to the devs working on Zorin 16. Since it's a fresh installation, you may want to try Zorin 16 beta, which has a more responsive ui and is more reliable. It's based on Ubuntu 20.04 with kernel 5.4 or 5.8. Check the hash of your download to match in order to avoid corrupted or incomplete images.
My experience with 15.3 with my new laptop left me conflicted of whether to continue with this os because not every solution worked completely on my machine. But since the release of 16 alpha that changed with hardware support, function combinations working and no issues on my machine. You're mileage may vary, but i doubt by much.
I'll check it out. Where can I find the beta?
Nevermind I see. Beta looks great.