I just found a little book I purchased maybe 15 years ago on how to keep Ficus trees alive indoor. One thing that seems to stay consistent, the more they're moved around, the more stressed they get and rop their leaves. This has shown to be true regardless of it's current conditions. I've seen many Ficus trees indoor, in the corner of a room, with very little light, doing wonderfully. Once they've been moved to the opposite corner, with just about the same light etc... they dropped all leaves.
My Ficus Alli has been the most resilient plant (from HD none-the-less) I've ever owned. That along with the schefflera that is about as old as me (30) which I have some cuttings rooting now and will be using in our Juvenile Meller's enclosure.
I've kept many ficus trees in my day and have come to learn they are very fickle in regards to being bothered but once established and left alone, will thrive for a long time...
Luis