I believe the AI is misleading you: I have removed nvidia_470 and nothing changed, except for even worse performance, because of course now everything is cpu rendered

glxinfo | grep "OpenGL renderer"
OpenGL renderer string: llvmpipe (LLVM 22.1.5, 256 bits)

I have managed to find an old livecd image from june 2025, and I have installed it. I have not installed nor updated any package yet. I could update each package until the problem occurs again, so that we would know which package causes it. Would this help? What packages should I upgrade and in what order? Do you have suspicions?

Checks on the livecd ISO image revealed that due to a bug in the images creation scripts all the recently published iso images were indeed the same image creared two months ago. So the livecd ISO image has been fixed today and the other fixed ISO images will be released within the next two days. Please note that the fixed livecd image has the same name and date of the one released last night so make sure you have downloaded it after the date of this post comment or check the MD5 reported on the site.

Contextually it has been confirmed that the bug in the application menu was caused by the absence of the plasma5support package and this has been fixed for new ISO images.

No other general problems have been reproduced, including the calamares installer which completed installation tests without crashing.
For any problem that would persist it is required to report after trying the flow based on the fixed live ISO images.

Thank you for reporting.

Thank you for looking into this issue.

I have now installed openmamba using the new livecd image.

The app menu does work correctly now in the live environment. At the end of the install process, calamares fails to unmount the partitions, but I don't think this causes the issues I am experiencing. Here is the calamares log file: https://termbin.com/0bax

I am experiencing the same crashes right in the first boot. I have not updated nor installed any packages. I have not run dnf at all. Please advise what to do in order to debug the situation.

Looking at the Calamares log, the installation kept the existing home directory, so all previous KDE/KWallet configuration files were preserved — including any corrupted settings. This is very likely the cause of the persistent crashes.

Please test with a new user account to confirm:

sudo useradd -m testuser && sudo passwd testuser

Log out and log in as testuser. If everything works there, the problem lies in the configuration files in your home directory.