Which wall cracks are problematic and which are not?

Good day. I have various wall cracks in my new apartment (now 4 years old). Visually, it does not look nice, of course. Apparently, whitewashing over it will not solve anything. But which cracks are actually serious and which are only visually unpleasant? For example, horizontal cracks next to the windows, doors? Or vertical cracks from the ceiling to the exterior walls (seen from inside)? The depth is hard to estimate. The width as well. The length is visible. Are there any rough guidelines here? Many thanks.

Pictures say more than a thousand words.

Pictures say more than a thousand words.

I am not very skilled with computers. Unfortunately, I cannot upload photos, etc.
That is why I have described the cracks.
So, can one not say that vertical cracks are worse than horizontal ones?
That cracks on the exterior wall are worse than interior walls? Etc.
What a pity.

Of course, someone can give you an answer. Which one do you want to hear? That the apartment is about to collapse or that everything is fine? The scale usually tends to "usual settlement cracks". That's all you can get without photos.

Pictures say more than a thousand words.

Good morning.
I really can’t manage to upload photos. I guess I’m already too old for that.
So, the building is exactly 4 years old.
Poroton bricks according to the description.
Construction time about 1 year, roughly from shell construction to handover.

PS: Can one test whether the cracks are still active as follows?
A thin layer of plaster over a part of the crack. If it cracks, the crack is still active.
With a very thin needle, I can determine that the cracks are usually about 0.4mm wide.