Tree is dropping green healthy leaves, they are developing a white border on the edges. It looks like bright white paint . Also some have a bright white splotch on the leaves. You can remove that , just lift it off. The tree is 33 years old. Out in the summer inside before frost.
Certified GKH Gardening Expert
This sounds like an powdery mildew issue. You can correct this using neem oil spray. Here is an article for more information on the care of the ficus tree: https://www.gardeningknowhow.com/houseplants/ficus/ficus-tree-care.htm