Has the dealer looked at the transmission? P0944 simply indicates loss of pressure but does not indicate why pressure was lost. I know it is is new vehicle but check the fluid level first thing. Next the pan will need to be dropped. Check both filters particularly the main filter. If the outlet of it is not firmly seated in the pump housing or the seal is damaged the pump will lose prime and not pump. Also, the filter housing needs to be checked for cracks which can also cause a loss of pump prime. Again, I know it is a new vehicle but sometimes these basic things get through the checks or just happen. If the fluid level is good and the filters are good, then yeah the trans has a serious issue.
Keep in mind if you go the NH Lemon law route the vehicle has to have been out of service for 30 business not calendar days. At that point, you can submit the demand for arbitration form to the MVAB. NH law requires the dealer to provide new car purchasers with the information about the NH Lemon law and the demand for arbitration form. Not sure on the length of time it takes the MVAB to hear a case or render a decision. The MVAB decision can be appealed to the Superior Court by either the manufacturer or the consumer. Once you file the demand for arbitration form, the manufacturer may halt any further work on the vehicle until the case is finally decided by either the MVAB or Superior Court. The procedure can take quite some time so be prepared and keep making your loan payments. Failure to make keep making the loan payments can cause you to lose lemon law protection.