I currently have a fresh Ubuntu 20.04 installed on my Vostro laptop with Nvidia's MX 230 video card. I installed the proprietary drivers doing this. Every time I try to increase or decrease my screen brightness using keyboard shortcuts my entire UI freezes for a little while before actually 'applying' it. Everything works normal using UI brightness sliders as well as executing
Code:
sudo su
"echo 200 > /sys/class/backlight/intel_backlight/brightness"
Following this post, here's my output:

cat /proc/cmdline
Code:
BOOT_IMAGE=/boot/vmlinuz-5.4.0-40-generic root=UUID=7163b0a7-caf2-426c-9cb9-ab5d1e148018 ro quiet splash vt.handoff=7
lspci -k | grep -A3 VGA
Code:
00:02.0 VGA compatible controller: Intel Corporation UHD Graphics (rev 02)
    DeviceName: To Be Filled by O.E.M.
    Subsystem: Dell UHD Graphics
    Kernel driver in use: i915
for i in /sys/class/backlight/*; do echo $i; cat $i/brightness; cat $i/actual_brightness; cat $i/max_brightness; done
Code:
/sys/class/backlight/intel_backlight
120000
120000
120000
pastebinit /var/log/Xorg.0.log
here's my pastebin

here's additional info about my nVidia card: