This is why it is so important to get a pre-drywal (stage) and 11 month warranty inspection.
On a pre-drywall inspection I had as you can see from the 1st picture some cracking in the foundation(which continued throughout the laundry and adjoining bedroom).
The 2nd picture shows how the cracking went throughout the house and was visible from the exterior.
You can see what the outcome is by looking at the 3rd picture. In this home the crack continued through 4 tiles in the kitchen dining room area. The tiles were replaced by the builder and cracked once again.
Most new construction homes are built on a post tension foundation which is super strong. So don't worry! Your house will not be compromised because of this, but it will effect the finishing's you see in your home. Whether it's cracks in the floors or walls, it's always a good idea to get these details documented to protect your future self and home.