Answer: Ficus are notorious for dropping leaves when they are moved. Typically it is due to lower light levels and dry indoor air during the winter heating season. Or, if they have grown a great deal and the leaves are dropping from the top portion of the plant, you may need to water them a bit more than you used to in compensation for the roots having filled more of the container. (Leaf loss from the lower portion can indicate overwatering.) Sometimes too a very dark and cloudy winter can actually make a big difference in the amount of light reaching the plants compared to a bright sunny winter with lots of sun reflecting the light.
But since this is much worse than before, it could also be that there is a pest problem. If you inspect the leaves and see stippling and fine webbing, then it is a case of spidermites. Treat these with commercially formulated insecticidal soap and try to raise the humidity if you can. A slightly cooler room temperature can also help. You might also want to look closely for signs of scale on the foliage (check undersides especially) and on the bark. These look like little discs and can be scraped off with your fingernail. Scale in particular is difficult to control so you will probably need to be vigilant in watching for them. They can be treated with insecticidal soap or with horticultural oil. Read and carefully follow the label directions including for reapplication. These are sold at garden centers. Read and carefully follow all of the label directions.
I hope this helps you trouble shoot.
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