I have had this issue with my jade plants for several years. All leaves develop a scaly texture after a while. New leaves regrow green and healthy. Some smaller leaves quickly turn silver and just fall off. All of my jade plants have this, but none of my other succulents seem affected. It also doesn't kill the plants, they are all several years old.
At first, I thought it might be sunburn since I have them under a grow light. But then the pattern on the larger leaves almost looks like something is eating through them. In addition, most images of sun burned jade plants I found online look a little bit different (the patches seem to be rounder and have a different texture).
Could this be some sort of fungal infection?
I found this old reddit thread which seems to be about the exact same issue. However, the OP never found the underlying cause.
Sorry, not gonna be much help as I don’t have an answer... Anecdotally, my many Jade plants grow very well while inside near a south facing window (I’m in the northern hemisphere). Maybe it has to do with the grow light or over watering?