Hello Kevin
Obviously I'm nowhere near you, so is perhaps not the best suited to advice you, but this is a common shrub here as well. What I think is happening here is that the soil has been so wet that the newly planted shrub hasn't had time to develop a good root system yet. Wet soil reduces root growth, so there is not a good balance between foliage and roots yet. This will correct in time. A little wilting isn't the end of the world and as long as this is not too bad and the plant recover during night, it will do no harm. As long as the soil is moist, I'd resist watering it as too much water will prevent it from growing a deep, extensive root system. Also, be careful with too much fertilizer as this also prevents a good root growth.
Of course if you have very hot and sunny weather you could try to shade the plant a bit. As the plant is otherwise healthy, I would absolutely not dig it during active growth.
