Well, this is highly abnormal for a new house to do this soo soon.
In a nut shell, the ground is settling to its norm and the home is not settling with it as one piece.
I am from Texas and we have big big big foundation problems due to drought and then floods. When the ground dries out it shrinks, when it gets water it expands. This movement is strong enough to move houses with it.
I would start a campaign of soaking your foundation regularly. The proper procedures are to soak the ground one foot from the foundation all around the home in the same or close to same time frame. For example if you only soak one side of the home one week and the other then next week, then one side will shift minutely while the other stays still. I water my entire foundation at the same time.
One night a week I hook up my four soaker hoses and run them all night. I have them secured to the ground with tent stakes so all that I have to do is to turn on the water.
Now for those lines, do not use mud or compound. Get a tube of latex caulk and squeeze this into the holes. You will notice that the cracks open up in the summer and close up in the winter, so you have to have a chemical that is elastic.
THEY WILL NEVER GO AWAY, NEVER NEVER NEVER. ONCE THERE YOU JUST HAVE TO MAINTAIN THEM. DON'T LET ANYONE TELL YOU THAT THEY CRACKS WILL BE PERMANENTLY FIXED.