As for dropping leaves, mine has done the same thing in the past, especially.

Elephant bush dropping leaves. HU 2 years ago. We have had this plant for about two months. It was doing well till recently it has been dropping a lot of leaves.
When we first bought it, it was full and bushy. some watering in summer and darn little in winter. Like; Save; HU thanked Embothrium. socks. 2 years ago.
Dec 17, Leaf drop can also occur if the elephant bush is underwatered. Not enough water causes the leaves to dry up and sometimes drop off. Elephant bushes should be watered more often in summer and less. Feb 19, It is normal for the plant to drop its lower leaves in moderation, as part of normal growth. As long as they are being replaced by new ones on top, it's nothing to worry about.
What you've got going on looks like dehydration to me. Either the plant is not getting water often enough, or it does not have enough roots to take up the water it does get. Jul 28, Commonly, Portulacaria Afra “elephant bush” loses its leaves prematurely because of the watering issues. Overwatering and underwatering, both can cause premature loss of leaves. The dwarf jade plant loses leaves when underwatered or during a drought to conserve its water storage.
It enables its survival mode when it is severely short on water. Jul 06, Leaf drop occurs when the leaves of the elephant bush fall off of the stem suddenly. This happens because the roots at the bottom of the plant have developed funguses from being overwatered too many times. It can kill the plant quickly, so you must take action.