Vertical crack in mortar of new home

We just finished building our new home in August. We recently found 2 vertical cracks outside along each side of our bay window. The mortar is even falling out of one of the cracks. We also have a small vertical crack in the mortar under our front door. I’ll attach pictures. Why would this happen? Our contractor claims settling but can’t see that as it’s only been 3-4 months since the brick was finished. I’ll add we haven’t been satisfied with our brick for various reasons. Any help would be appreciated!