I agree, any sudden change will affect a Ficus that way,
it's like the plant equivelent of a temper tantrum.
I once saw one drop nearly every last leaf because it was
moved from the right side of a sliding glass door to the left side.
They nearly always recover just fine - but -
be sure you don't over-water during this period,
with less foliage, it may need less water than you're used to giving it. :wink:
Use your fingers to feel about an inch or so deep into the soil.
Also, don't fertilize the plant until it grows some new leaves.