Yeah that might be it. Sddm is a display manager, you might be using it for your login screen.

You might be able to work around it by just setting the service to restart automatically, so that it comes up properly once a display is attached. But if you can, I would try reproducing it on a fresh and fully updated install, and open a bug report to the maintainers if you can. Linux developers generally try to make really sure their programs don’t crash like that.

Unattended-upgrades or dnf-automatic

https://jellyfin.org/docs/general/clients/codec-support/

Boot log/kernel/dmesg, X/Wayland/kde primarily. Been a long time since I’ve had to troubleshoot something like this so I don’t know the new kids on the block. Maybe upstart or dracut? Whatever manages the boot process now

That seems strange. What’s in the log?

So what does it have to do with Linux?

Believe all you want, reality doesn’t care.

I would recommend not touching system apps unless you have a very good reason for doing so. And be willing to risk breaking your device.