Cracks in the screed. Problematic?

Hello,

we have the handover of our house next week. Today we thoroughly inspected the house and noticed that long cracks have formed in the screed on the ground floor. In addition, the corners of the terrace doors are rounded. The builder says these are normal stress cracks and not a cause for concern. Do these cracks have to be repaired necessarily? What happens if we just lay our vinyl floor over them now?

And does anyone know what those 'cables' (last picture) in the screed are?
Thank you very much in advance

So, regarding the cable, what goes where the cable comes out? That's probably what it's for. I don't really see any cracks, it looks more like a decoupling mat that's inside there and sticking out, for whatever reason. And about the corners, not nice but basically unproblematic. You will definitely need to apply a leveling compound under your vinyl.

So, about the cable, what is supposed to go where the cable comes out? That's probably what it's for.

Nothing goes there anymore. Just the floor on top of it. These cables also lie in other rooms.

I also don't see any cracks. Then it must be that "the cable" is somehow used for moisture measurement? The corner is not nice to look at for us, the screed layer would say "Perfectly filled. Tiles or parquet over it and that fits."

Thanks in advance, I hadn't even thought about the decoupling mat. Cracks can be seen better in these pictures. The question is whether these cracks necessarily have to be repaired

Since the decoupling mat is probably laid there, I say that it is normal for the screed to crack there.