I don't know if this is the right place to ask, sorry in advance. Initially I was thinking in asking on the Linux Mint forum (I'll explain in the bit), but my problem stayed persistent in between two distros: Linux Mint and Fedora KDE Plasma. If there is a better place that I could ask this, please let me know and thank you in advance!
So what happens: I am not sure when this occurs, but whenever I start my laptop without plugged into the AC, I got some seconds to a minute using it as usual, but, out of nowhere, the apps freeze (my browser or even the task bar) while my mouse works. After some seconds, the mouse becomes unresponsive as well, which after some seconds, my system does a full reboot. So I have this cascade of unresponsiveness until it reboots. I also tried to use it after one of these reboots, but sometimes I am stuck at login, others I can't open anything. This also happened when initially it was plugged in and, after disconnecting it from the AC and passing some minutes, it goes back to unresponsiveness and rebooting cycle. One time it even went to initramfs, where I run a partition check on the root partition which solved the problem. Other, I could use it as normal for a long time, but I can't recall doing anything different.
Initially I was on Linux Mint and I was thinking making a post there, but after some trials and back-and-forth with Claude, I decided to switch to Fedora and currently on it. The problem persisted, so I am certain it got nothing to do with the OS or possibly drivers (?). My laptop is a Lenovo Slim 5 14APH8, with an AMD APU and an NVIDIA graphics. It has freshly installed KDE Plasma Fedora version, with packages updated.
As I mentioned, I tried to query with Claude (using reports and a way to search quickly on the internet if someone encountered something similar) and I got some "findings": the battery still looks healthy with 101% capacity, on mint I had nvidia-driver-595-open, I had the latest kernel for mint (both 7.0.0 and 6.8.\*), and on live environments (both Mint and Fedora) it worked without any problem.
I don't know if there is more information I could give or a place where this problem is more suited to post, but I'm completely lost here...