Cannot boot into Kubuntu 20.04 LTS: CPU pipe A FIF underrun

Problem: I'm attempting to boot into a fresh install of Kubuntu 20.04.3 LTS. I get past the Grub menu screen, but I get stuck at a black screen with only one log which is this error: [drm] *ERROR* CPU pipe A FIFO underrun.

I've tried: I've tried disabling Intel C-State as described here: https://unix.stackexchange.com/questions/588457/drmintel-cpu-fifo-underrun-irq-handler-i915-error-cpu-pipe-a-fifo-underru. Which involves editing the Grub config under /etc/default/grub and adding the intel_idle.max_cstate=0 option to the GRUB_CMDLINE_LINUX variable.

I have also tried this: https://www.dell.com/community/Linux-General/XPS-13-7390-Ubuntu-Screen-flickering/td-p/7430121/page/3. Which involves disabling i915 PSR by adding i915.enable_psr=0 to the GRUB_CMDLINE_LINUX_DEFAULT variable (since I've seen that this has worked for some people, which I still don't understand what it does).

But no dice.

Has anyone encountered this and would know how to fix this?

I've been able to make modifications to my Grub config and lookup my system specs by using a live USB.

System configuration:

$ inxi -b
System:
 Host: kubuntu Kernel: 5.11.0-27-generic x86_64 bits: 64 Desktop: KDE Plasma 5.18.5  
 Distro: Ubuntu 20.04.3 LTS (Focal Fossa)  
Machine:
 Type: Laptop System: LENOVO product: 20TK001FUS v: ThinkPad X1 Extreme Gen 3  
 serial: <superuser/root required>  
 Mobo: LENOVO model: 20TK001FUS v: SDK0R32862 WIN serial: <superuser/root required>  
 UEFI: LENOVO v: N2VET33W (1.18 ) date: 08/11/2021  
Battery:
 ID-1: BAT0 charge: 80.3 Wh condition: 80.3/80.4 Wh (100%)  
CPU:
 6-Core: Intel Core i7-10750H type: MT MCP speed: 1000 MHz min/max: 800/5000 MHz  
Graphics:
 Device-1: Intel UHD Graphics driver: i915 v: kernel  
 Device-2: NVIDIA driver: nouveau v: kernel  
 Display: x11 server: X.Org 1.20.11 driver: modesetting unloaded: fbdev,vesa  
 resolution: 1920x1080~60Hz  
 OpenGL: renderer: Mesa Intel UHD Graphics (CML GT2) v: 4.6 Mesa 21.0.3  
Network:
 Device-1: Intel Wi-Fi 6 AX201 driver: iwlwifi  
Drives:
 Local Storage: total: 484.44 GiB used: 3.24 GiB (0.7%)  
Info:
 Processes: 281 Uptime: 13m Memory: 15.30 GiB used: 680.1 MiB (4.3%) Shell: bash  
 inxi: 3.0.38

So far I found a potential fix. I'm not entirely sure if it fixes my initial issue. But here are the steps I took:

1. Cleaned the partition
2. Re-installed Kubuntu/Ubuntu
3. Booted into safe graphics mode
4. Installed nvidia-driver-470: sudo apt install nvidia-driver-470

To date, I've been able to restart, and boot successfully into Kubuntu.