Take it back to the dealer's service dept and have them diagnose and correct the problem. It may be a problem with the converter charger, connections between the converter charger and the house battery, and improper setting of switches. If there is a switch marked "storage" or "aux battery", try switching it. Also make sure generator is providing power into the rig via an automatic transfer switch ( if you have one) or plugging the shore power cable into the side of the RV generator accessible in an adjacent cable storage compartment.
New rigs often have problems like this, have courage.