ASUS TUF DASH F15 RTX 3060 Laptop

Good evening all of you,
I have been troubling with the following problem now for about 3 days.

I have installed Ubuntu 18.04.5 LTS on that machine. Everything is running fine. No error during installation. But until I tried to install the Nvidia-Driver. The installation itself is looking good and no errors are visible. But as soon as I reboot to make all changes apply, the machine freezes in the purple screen during boot process.
Somehow that has to be related to the Nvidia-Drivers because I have rebootet the machine a lot of times before the installation of the Nvidia-Drivers. And I have reinstalled the machine a lot of times now. As soon as I install the Nvidia-Driver my machine stops booting.

Is that already a known issue? How can I fix that problem. I need the machine to run on ubuntu 18.04 with the Nvidia-Graphics card.

Thanks.
L.