Here’s my two cents. My hunch is that GNOME Wayland desktop environment is a contributing cause for systems with Nvidia hanging after resuming from suspend. I have been using NixOS for about half a year now. With the default GNOME Wayland DE that came with the NixOS installer, I always had issues with wake from suspend. Once I switched over to Hyprland and played around with some kernel params, the wake from suspend issues disappeared.
Here is my minimal working config. Note the hardware and boot.kernelParams section. GitHub - Compute-Dragon/nixos-nv-sleep