Display problems - horizontal blue and purple lines

Good evening,

since this morning, without anything happened to the device, my MacBook is presenting strange display problems.

The display shows horizontal blue (mostly) and purple lines moving vertically on the screen.

There are five columns of those lines.

In addition, a green transparent bar covers half of the left side of the screen.

If I take a screenshot, the lines are not visible.

It seems that the lines do not show particularly on white background (where instead the green bar is very visible).

It seems that some windows generates more lines (i.e. youtube shows a huge amount of lines, while watching the desktop makes them almost disappear).

We tried resetting the NVRAM (https://support.apple.com/en-us/HT204063) but it did not solve the problem.

Here are some photos:

Thanks in advance for the help.