We started out with a very healthy rubber tree then slowly all the leaves began to droop.
What Is Causing the Leaves of Our Rubber Tree to Droop?
Certified GKH Gardening Expert
Overly wet soil can cause drooping. It could have been overwatered. If it was overwatered, even once, it may have root rot. This article has more information: https://www.gardeningknowhow.com/plant-problems/disease/treating-root-rot-gardening-tips-for-housplants.htm