A few things.

The shock of planting will make the flowers drop, especially if the root ball is loosened some (which should be done btw).

No need to over water. Every three or four days until it adjusts should be plenty.

Azaleas and rhodos are sensitive to the chlorine in some municipal tap waters. Either try to use water from a rain catchment system or water if only absolutely necessary.

Don't over fertilize or feed.