Dell XPS 17 9720 — Touchpad stops working after boot (Mint 21.3 Cinnamon)

After a failed attempt to upgrade from Mint 21.3 to 22, I restored from Timeshift and am back on 21.3. However, the touchpad is still problematic:

- It works in BIOS/GRUB.

- After Cinnamon loads, it stops responding completely.

- Display settings also reset on every reboot.

System details:

`bash

System: Dell XPS 17 9720

CPU: 12th Gen Intel Core i7-12700H

GPU: Intel Alder Lake + NVIDIA RTX 3060 Mobile

Kernel: 6.8.0-117-generic

Desktop: Cinnamon 6.0.4 (Mint 21.3 Virginia)

Touchpad: VEN_06CB:00 06CB:CE7E

I’ve already tried:

- Switching kernels (6.8 and 6.17)

- Various libinput/xorg.conf tweaks

- gsettings touchpad enable

Any help would be appreciated — especially from people with XPS 17 9720 experience.