How often are you offering food? Are you handling the boa at all? If the boa refuses food, give it several days or even a week before offering food again. If it's not feeding, don't handle it. The boa will need time to acclimate to a new environment. Dumerils can be shy boas and dumerils babies are not as easy going as redtails about a lot of handling. As long as the boa has good body weight, the husbandry is correct and it otherwise appears healthy, I wouldn't worry. Leave it alone in a proper setup in a quiet area of the house (if one doesn't exist, cover the cage with a towel or sheet to provide privacy). After a few days of quiet, offer a prey item in the early evening or at night. It would also be a good idea (as already mentioned) to find out if it was feeding beforehand, and if so, what it was feeding on.