Soil pH: in alkaline soil (pH>7) calcium, magnesium, phosphate and a range of micronutrients especially iron become less available to plants. So between pH6 and pH7 rhododendrons etc often suffer from yellowing of the leaves which can be treated with a dose of Epsom salts.
Morning ridgiemum Like most everything in life, gardening is a learning curve.... Don’t give up on your azaleas just yet or dig them up. They might simply need time to settle in Can you post a picture of them? We might get an idea of how well or not they are growing.