Leaves Dropping on a Large Potted Camellia Plant in a Shade House
The plant is quite a few years old and in the past has done very well, flowering and looking very healthy. But over the last two or three years has been having this problem. It still flowers quite well though. The ends and edges of some of the leaves go brown too. I have never re-potted it.
It sounds like the plant has rust fungus. This article will help: https://www.gardeningknowhow.com/plant-problems/disease/learn-about-plant-rust-disease-and-rust-treatment.htm