[Installation] Post installation troubles. screen black with irregular pixel distribution and lines

[Ecomedians]

Hi everybody,

after many years spent using MacOs, I decided to pass to Linux. I am not so expert then.
After having installed Kubuntu (20.04), I was able to update the software to the version 5.4.0-51 by using recovery mode, because normal boot does not work. Namely, if I start normal mode this is what appears:

https://drive.google.com/file/d/18vY...ew?usp=sharing

Here follow specs of my PC:
Desktop
Intel core i7
Nvidia GeFroce rtx 2060
32GB RAM
3 HDDs (one for data, and two for Windows and Kubuntu respectively)

Thanks for your help. Please forgive me if I have forgotten to put information about the system or the software.
Have a nice day

[Teunis]

Two questions:

What kernel are you selecting?
Do you have the NVIDIA X Server setting module installed?