Why my jade plant leaves becomes yellow and then reddish?
Certified GKH Gardening Expert
It sounds like it may have root rot. This article will help: https://www.gardeningknowhow.com/plant-problems/disease/treating-root-rot-gardening-tips-for-housplants.htm
Jade plants are succulents and they need very little water. They should never be left in standing water and the soil should be allowed to dry out between waterings.