This image shows the location of this plant around 9am with morning sun. It is the smaller one in the rear.

Because pot grown rhododendrons/azaleas are in a peat based mix, it frequently happens that the soil is moist, but the root ball of the plant is bone dry. Only way to tell is to dig it up. If dry, soak in water for 30 minutes or so and replant. Water when needed by directing just a trickle of water at the base of the azalea(s). You want to keep the roots moist without soaking the soil.