Kernel not restoring backlight brightness level after sleep/suspend on laptop

[lunelovehearn]

for some reason, when closing the lid/manual sleeping my laptop, it seems like the kernel doesn't restores correctly the values to restore the backlight brightness as intended. instead, the brightness gets stuck at 70% as the minimum value then increases from there to 100%, when it should not do that. this happens under AMDGPU on vanilla arch. from my research, the systemd services in charge of managing the values are working fine. I know this as I switched to the Arch LTS kernel and the issue is gone. so some regression may have appeared again, as there were reports of systemd having this issue some time ago, but this time seems like it's related to the kernel, based on my research.
edit: all vanilla arch kernels work fine and don't have this issue. it's only cachy kernels the ones with the issue.

System Specs attached:

[1Naim]

Please try the kernel from https://share.cachyos.org/x86_64_v3/kernel/suspend-revert/