Water coming in through weep holes during hard rain?
"is it possible the rain is being driven into the weep holes?"


yes, but the weep holes are supposed to be on the outside of a moisture barrier, so rain driven in still should not enter the house.


"is this more likely clogged weep holes?"


no, the holes are designed to "weep", and are difficult to completely clog.


"is this an issue with the way it was built?"


yes, I suspect a structural defect such as incorrectly installed flashing above the window or inadequate/incorrectly installed moisture barrier.


You absolutely should pursue repairs through the builder's warranty.