This is a brief update:

* Removing quiet from boot works, splash may remain there

* Adding fbcon=nodefer to boot works. Under the hood is more or less equivalent to removing quiet

* Kernel 6.11 seems to work.

* USB-C monitor output works (it may take 30 seconds to shutdown, but it does)

It is not clear yet the exact cause, it looks like some race condition between drm, plymouth and maybe simpledrm. There were already issues with plymouth and sddm.

Sorry for the inconvenience and we hope at least those simple workarounds do the trick until we found a proper solution.

Thanks to everyone! I did the edit, and it works. 

Good morning,
Removing the quiet from `GRUB_CMDLINE_LINUX_DEFAULT` line in `/etc/default/grub` and then doing `sudo update-grub` should update the GRUB arguments, and in the next startup, so that Linux can recognise the change of `GRUB_CMDLINE_LINUX_DEFAULT`, should work.

Editing said file can be done in terminal with `sudo nano /etc/default/grub`

Regards,

I think the apt-get is a mistake

Edit this file:

$ sudo -e /etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash si=1 fbcon=nodefer"

$ sudo update-grub

 Thanks Enrique.

Can you give precise instructions on how to "remove quiet from boot"? (I'm not a tech person.)

Appreciate it!

It's my case too!

Yes, I have an external monitor attached. Thanks for looking into this!!

We are researching the source of this issue, looks like is somewhere in amdgpu module from 6.14 series when there is an external monitor attached (are you?).

Meanwhile, try to disable boot splash (remove quiet splash from grub) and test it. We have been lucky with that.

Yes, I noticed this morning that when I do a PowerOff from GNOME, the machine doesn’t actually shut down (the LED stays on), and if you don’t notice, the battery ends up draining...

Followup (in case anyone from Slimbook is monitoring and can advise):
- In my case, I believe this started after the kernel upgrade to Linux 6.14.0-1013-oem
- If I use the "shutdown" command or the physical button to power off, there is NO battery drain

Esto mismo me ha pasado esta misma semana. Salí el pasado jueves de viaje de trabajo y me lleve el Evo totalmente cargado. Cuando lo arranqué al día siguiente después de no más de 14 ó 16 horas me encontré con la batería totalmente drenada (0%). Algo extraño la verdad. Estoy usando Slimbook OS.