This issue is a long time coming. I got a mini pc (Asrock Deskmini h110, i5-6400, 16gb) that I have used for a long time with Kubuntu/Kde Neon, and most of its life, it worked great. Some years ago, it started freezing, especially at Graphic intensive workload, so I thought some hardware issue and converted it into a NAS and it worked absolutely fine as well for a couple of years there too. Recently my wife needed a Windows PC to do some work, and since I had upgraded my NAS, I repurposed the same PC and installed Windows on it, and it worked absolutely fine for her too. Then I decided to check some Graphics intensive workload, like 3d benchmarking stuff, and it didn't freeze once. I was delighted, and thought maybe I didn't investigated the issue the first time, and the PC was fine all along. So I reinstalled Debian 13, and lo behold, the issue came back. I found out while I was using IKEA's 3d kitchen planner. So I replaced distros, and it froze on Ubuntu and CachyOS as well. I tried switching between Wayland and X11, switched browsers, but PC freezes seconds logging into IKEA's kitchen planner (as soon as 3d graphics are loaded). I reinstalled windows, and my wife has been designing a kitchen in IKEA's 3d kitchen planner for over an hour now, and it hasn't frozen once. What's going on? How do I even investigate this?
I have reinstalled Linux and had sudo dmesg -w running, but no logs are captured before it's frozen. I have reproduced the issue multiple times now on Linux, and not once it froze on Windows. I have also done memtests, and tried multiple disks both nvme and sata. Also have tried multiple browsers with apt and flatpaks. I really need Lemmy's collective intelligence to help me here.
Update: Well system stopped hanging with 'nomodeset' as boot parameter, confirming that it's Intel 915 driver. I tried variety of Intel related kernel parameters like psr, dc, guc, even messed with Intel cstate, but it hanged every time Intel 915 driver is even loaded. So ???
Not sure this is the answer, but going to throw my two cents. If you try and it works let us know.
When I got back into linux a couple years ago I hopped through all of the distros you mentioned. The last one being KDE Neon. When I first found it I absolutely loved it. Decided that was going to be my main distro and started migrating all my systems which is a couple laptops, gaming desktop, and mini PC.
Over time I found that I was having minor, but consistent hardware issues. Similar to yours, freezing, and other gpu issues. It was most apparent on systems that had newer hardware. Looking at the specs for your mini PC it seems a bit older than what I have so again, not sure this applies to you, but I found my saving grace in Fedora. My issue specifically was the older kernel Neon uses not interacting well with my newer hardware and in some cases not having access to some hardware features. Fedora had a KDE spin otherwise I wouldn't have done it. It has been my daily driver on all systems since.
TL;DR: Try Feodra KDE Spin or any distro that ships with a more up to date kernel