G15 5530 NVIDIA and kernel 6.8 problem solved

with the same drivers all the way up to ubuntu 2510 with kernel 6.14.0-23-generic

I also managed to successfully use 25.04 with 6.14-hwe kernel with nvidia-driver-575-open. Seems like newer configurations are working again. Tho no luck with nvidia-driver-570 (non open).
The only issue so far is the display not waking up, and the system not coming back from sleep in Wayland.

I would like to leave here three very common steps when trying to debug NVidia on Linux (a complicated relationship since ever).

1. Secure Boot.

Even if your Linux distro is working fine with Secure Boot, by installing NVidia's proprietary drivers, there might be problems with secure boot.

It's a very simple troubleshooting method, but should only be used for troubleshooting (unless you really know what you are doing). NOT A PERMANENT SOLUTION.

If found that Secure Boot is indeed blocking the driver from loading or even preventing the system to boot, there are proper ways to sign the kernel module and enrolling it on the Secure Boot as "trusted" (e.g. MOKutil).

Information about disabling Secure Boot should is on the product's manual.

2. The GRUB cmd parameter "nomodeset"

Some distros have problems initializing the GPU early on boot. Setting this parameter as boot parameter on GRUB has been a way to boot otherwise unbootable systems with a NVidia GPU. I've experienced this with Manjaro, setting the parameter was the only way to properly boot (in my case with Hybrid Graphics disabled). Again, this should be a temporary solution, restricted to before the proper installation of the proprietary drivers (check below).

3. The "nvidia-drm.modeset=1" parameter

After installing the proprietary drivers (generally you'll want the "open" versions - "open" here is by no means the open-source Nouveau driver, it's the proprietary driver with the kernel module available as source-code instead of being a monolithic driver like it used to be. This is generally considered an advance on how NVidia supports Linux actually).

Well, after properly installing the NVidia drivers, you'll probably want to try removing the "nomodeset" parameter and using this one instead, ideally getting proper support for early kernel modesetting. I have not personally tested this, though, but the below article explains it very well:

https://support.exxactcorp.com/hc/en-us/articles/32048852204951-Understanding-nomodeset-vs-nvidia-drm-modeset-1-on-Linux-Systems-with-NVIDIA-GPUs

Finally, there's nothing really preventing any modern Linux distro from booting on this machine. Some hardware vendors (in this case, only NVidia, I believe) are historically troublesome to work on Linux. Most of the time they work, but not automatically like hardware supported by mainline Linux.

With these kind of issues, Dell most probably won't help, for many reasons. Discussing the ethics behind this might be harder than it seems; while I personally won't say it's completely fine, it's hard to think a business would keep supporting - patching, almost "hacking" the system and/or drivers in order to work properly - like, forever.

There's one thing about Dell that doesn't seem to make much sense for me: their policy of simply answering these questions as "it's not supported by the platform/machine".

This sounds misleading, like if it would never work. I personally think that a proper, more in-depth explanation (and even sincere, one single article explaining the difficulties that prevents them from being the "bridge maintainer" between NVidia or other "difficult" vendors and the whole world of Linux distros) would be better than the current approach, both for their image towards users and the other way around (but, of course, this is only my opinion).