Hello Ryan,
That is nice starter material...Kanuma can hold quite a bit of water and can sometimes break down faster than we would think..Couple this with azaleas having fine, haih like roots.. and root rot or an unhealthy root system will sneek up on you awfully fast... Especially if it was not sifted well before usage. Also as Victrinia pointed out, since it was pruned, it will need less water. Also and just as important, a sick tree needs less water since it is not taking in the same amount of water that a healthy tree would take in.
Also, while the tree is sick..All fertilizing and feeding should be stopped. Only when the tree begins to recover, should feeding, maybe limited doses, be offered. However, like Victrinia said, if it is an iron deficiency, adding iron will obviously help. if not, it may do more harm than good...
Rob