Yet Fedora 44 just restarted mid working on something without asking killing ungracefully all VMs and containers running. How do i stop Fedora from doing that?
The most common cause of forced reboots is the packagekit-offline-update service, which applies updates during shutdown or reboot.
I mask mine but You will have to update manaully after disabling it.
sudo systemctl status packagekit-offline-update.service
○ packagekit-offline-update.service
Loaded: masked (Reason: Unit packagekit-offline-update.service is masked.)
Active: inactive (dead)
maybe wait for other to reply as well before doing this method.
If help is needed I will be happy to help on how I disable and mask that service.
$ sudo systemctl status packagekit-offline-update
○ packagekit-offline-update.service - Update the operating system whilst offline
Loaded: loaded (/usr/lib/systemd/system/packagekit-offline-update.service; static)
Drop-In: /usr/lib/systemd/system/service.d
└─10-timeout-abort.conf
Active: inactive (dead)
Is this good or bad news?
It’s how I thought it would read. 
If you want to disable/mask it then, I use this:
systemctl stop packagekit-offline-update.service
systemctl disable packagekit-offline-update.service
sudo systemctl mask packagekit-offline-update.service
All that is pretty straight forward, but if you have a question just ask about those commands.
I would at the least logout and back in again to set this in a new session.
That’s not normal behavior, whatever complaints we might have for the the way the default software managers are handling automatic updates.
I would look into the journal limited to the boot that resulted in the sudden reboot and check if indeed Discover/PackageKit is the one causing the reboots.
FWIW, offline upgrades can be performed with dnf as well.