Random pixels appear on screen

I have a MacBook Air 2017 13''. Since buying it, I've noticed that random pixels appeared on the screen, however I brushed it off. Since I installed Catalina, random pixels are becoming more and more apparent.

As suggested in response to my previous post, I have tried creating a new user and using safe mode, with no result. These pixels appear anyway, even in the login screen (before I select my user and enter my password).

What should I do?