Hi Mike, to me your plant is behaving normal as it should indoors during winter. It is usual for tropicals to slow down a bit in winter and to drop the older leaves below. The plant is just shedding the older leaves below and trying to provide for the top part. It will return to its usual vigor in Spring. Just make sure you do not make that plant sit in water. New growth comes at the tips. Looking at it, the top part looks lush and happy.
