Maybe try Endeavour? I haven't used Cachy, but I've heard it's a little more unstable. And I know I've gotten Endeavour to work.
Here's a list of what I've got actively installed now, in case it helps:
SP4 - Endeavour, SP6 - Ubuntu vanilla, Mint Cinnamon
I don't have access to a 5, otherwise I'd play around and try to help.
That's... odd. I wonder if it's a Garuda thing.
I've now installed four different flavors of Linux on a variety of Surface devices. Haven't had that happen to me, but I also didn't try Garuda.
Sorry to hear about that.
Look at how many Americans would voluntarily die themselves just to prevent "unworthy" people from getting free health care.
These people exist.
You add the new kernel's repository to your repo list. During updates, Pacman will pull what it needs from the various repos.
That's the short-short version. Possibly not technically accurate, but that's basically what it does.
After I ran the setup commands, edited the config file, then ran the command to install + update, it updated without me having to manually select any files.
Yeah, I'm sure Bluetooth is just from something I missed. Some config I need to update, or something.
Touchscreen and pen both work perfectly with the new kernel.
Quick follow-up, because tonight I installed EndeavourOS on my Surface Pro 4. (It's not Garuda, but it's still Arch.)
If you can follow instructions and copy/paste Pacman commands, you can install the Surface kernel. I did hit a couple of unexpected errors along the way, but the error messages were very specific. So it was easy to resolve them.
The instructions page is written very well, and there's a whole section dedicated to Arch.
There are only two things I haven't done yet: set up secure boot, and enable Bluetooth. Both of those things are pretty well documented, I just haven't tried to do it yet.
Either way, as long as it's painted in stripes. It has to be stripes, right?
A powerhouse of a gaming PC ;-)