Display artifacts and screen flickering on boot

Help
1

When I boot up my system, weird glitches and flickering are present until SDDM starts up. I am looking for some way to fix these glitches without SDDM so I can use TTY display managers such as ly, and also use my BIOS menu more easily without my screen constantly flickering. Please let me know if you have any solutions, attached is a recording of the screen during the startup process.
YouTube link
Info:
GPU: NVIDIA GeForce RTX 4060

lsmod | grep -e nvidia
nvidia_uvm           4009984  0
nvidia_drm            143360  43
nvidia_modeset       2195456  14 nvidia_drm
nvidia              15888384  284 nvidia_uvm,nvidia_modeset
drm_ttm_helper         16384  2 nvidia_drm
video                  81920  1 nvidia_modeset
ecc                    49152  2 ecdh_generic,nvidia

It didn’t always do this and just started a month ago. It happens in the BIOS menu before Linux even boots, so I’m just looking for some way to fix this within NixOS.

2

That honestly looks more like a hardware problem than a software problem. Check the connections between your PC and monitors, see if the cables are tightly connected. Try using a different set of cables as well. Additionally, if you’ve got extra hardware, try swapping out to a different GPU, or switching to/from an iGPU.