Crack in plaster or wall

Our house is now almost 6 years old and from the beginning, fine hairline cracks have repeatedly appeared on the exterior plaster, especially on the gable walls. The construction management at the time always had the cracks sealed again. This year, for whatever reasons, the cracks that had already been sealed have reopened again as every year, along with countless more. In my opinion, the worst thing is that we have now discovered that three cracks go through the entire masonry. This means that just as the crack runs on the outside of the plaster, it can also be seen inside behind two radiators in the interior plaster, and one is visible through the cracked woodchip wallpaper on the gable slope. The house was built with Ytong stones and completed within three months. Such cracks are no longer normal, are they??? Well, they are not wide, 1-2mm, but going through the masonry?? Oh, by the way, in case it should be of importance – 90% of the cracks are on the gable side facing southeast, and 9 meters away from this side there is a road. How is the warranty situation with such cracks? Sealing the cracks has brought no improvement, above all, it has not held. What else can we do? Thank you in advance