If your plant was outside in bright light, then brought indoor, leaf drop is not uncommon, it needs to get adjusted to the lower light levels, so give it bright light and some direct sun if that's the case.
Leaf drop can occur after re-potting. If the new pot is too big, extra soil keeps the roots wet which they hate, get rid of any of the excess soil and move to smaller pot. Have just one inch between root-ball and inside wall of pot)
Check for any pest that might be on the leaves.
Water plant well when dry, check soil weekly.
Keep out of cold drafts.