In order to ask a meaningful questions about plant disease, you'll need to be able to describe the appearance of the affected parts of the plant. Regarding leaves, think about such things as the color of the leaves (tan, dark brown, yellow,) shape (curling up on edges, or down on edges, folding from center vein, etc.,) spots ( yellow, brown, black, with or without holes, dry or moist, discreet edges or blurry areas, etc.)
The most important defense agains disease and pests is a strong healthy plant, so you always need to consider the culture of the plant. Sapodilla needs a lot of water, so this is the first thing to make sure of. Here are a couple of articles that will help you with the care, and tell you what to look for in terms of pests and pathogens: https://www.gardeningknowhow.com/edible/fruits/sapodilla-trees/growing-sapodilla-fruit.htm
The very best approach to dealing with plant problems is to get an expert diagnosis in person. You can take samples of leaves, also branch and soil, to the nearest horticultural station. Information on these should be available through the nearest botanical garden.