Need help with PRIME render offload

Maybe it helps to preload the kernel driver. Try this:
Create /etc/systemd/system/load-nvidia.service

[Unit]
Description=Load Nvidia driver
Before=display-manager.service

[Service]
Type=oneshot
ExecStart=/sbin/modprobe nvidia

[Install]
WantedBy=display-manager.service

and enable it using
sudo systemctl enable load-nvidia
make sure /sbin/modprobe is the correct path. Then reboot.