I suspect you have a Strelitzia alba, not a Strelitzia reginae. The former does better in lower light and is more commonly sold for indoor use. It rarely flowers. The flowering Reginae is what is more commonly grown outdoors in very warm climates. Unfortunately, it seems most retailers call both species Bird of Paradise.
Plants have a wide range of light tolerance, but it can take a long time for them to adapt to big changes. Outdoor sun can be from 10 to 100 times more intense than indoor direct sun.
