Laptop screen is behaving extremely strangely?

I have a Dell Inspiron 15 3501.

With the following components:

Intel Core i5-1135G7

8 GB DDR4 RAM (2,666 MT/s)

256 GB SSD (approx. 100 GB still free!)

Windows 11 Home.

For some time now, I've been having the problem that the screen suddenly starts doing strange things… for example, right now, for a fraction of a second, I see a green line that stretches across the entire laptop screen (from the far left to the far right)… flashing…

Sometimes it goes down briefly or something similar… or the image (e.g. the browser window) moves quite jaggedly in some direction…)

Today it got really bad, it got to the point where the screen kept going black (i.e., the backlight was black). However, if you pressed CTRL + ALT + DEL, it kept going back and you could usually get back to the screen by canceling. For a short time it went black again and I was able to get back to the screen using the key combination…

Later it became horrible, the screen was really distorted, you could see how the writing became very unclear and distorted for a short time… the mouse was also very pixelated.

You couldn't really work with him anymore.

I've noticed that this often happens under load, but it has also happened completely before (with no load, with only the browser window open and 2-3 tabs)…

After I restarted it, everything was fine for a while… then it started happening again until now…