Brightness not working ONLY with LVM encrypted volume

Hardware Support
1

Zorin 18.1 Core installed on my Dell Latitude 5490 without encryption and both the keys and on-screen slider work perfectly for brightness control.
However, I want additional security for this laptop as I take it out & about with me, so I re-installed enabling the LVM encryption - everything functions as previous EXCEPT the brightness. The keys do not change the brightness (you see the screen notification at the bottom of the brightness going up and down) but the brightness does not actually change - it is at a low or possibly off setting. The slider also makes no difference either.
I have completed a software update and rebooted (turn it off and on!) but still the same issue.
Wayland
Firmware 1.38.0
Intel UHD graphics.

Long time linux lover, first time community poster. Be kind I'm not young anymore :slightly_smiling_face:

Thanks all

2

Hello and welcome,
You can try this
Edit GRUB defaults:

sudo nano /etc/default/grub

Find the line starting with GRUB_CMDLINE_LINUX_DEFAULT=
change it to
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=native"

If you see acpi_backlight=video or acpi_backlight=vendor , replace it with acpi_backlight=native (don’t keep multiple).
Update GRUB and reboot:

sudo update-grub
sudo reboot
3

Welcome to the Forum!

Try it with switching to Xorg. To do that, got to the Login Screen and click on Your Profile so that the Password Field appears. When it is appeared, You should see in the bottom right Corner a Gear Icon. Click on it and choose the Option ''Zorin Desktop on Xorg'' and then log in.