Q.Sick Jade Plant
This was a beautiful jade plant and has now gotten what looks like burning on the leaves. It has been in my sunroom for several years and I seem to recall that it did the same thing last year about the same time and then recovered winter/early spring. It is fine year round in the same location until about late August. Please see the attached photo and let me know what I should do to improve/save this plant.
This could be basically a sunburn due to excessive light. Since the problem appears in August, it probably does have to do with the additional sun or heat. Keep the plant out of direct sunlight for a few weeks (but do give it normal indoor light) until it begins to recover. Then, perhaps you could place it under the shade of another plant in the sunroom or keep it in another location in the house.
Also check this article in case it is any other problem:
https://www.gardeningknowhow.com/houseplants/jade-plant/black-spots-on-jade-plant.htm