From what I noticed in my figs in pot, heavy pruning does decrease productivity the first year on certain varieties and could even totally eliminate the crop for that season.
Most of the energy goes into the new growth. In your case I suspect that the same thing is happening. Try to protect your tree in winter and see what happens.
Make sure that there's enough nutrition in the soil by fertilizing on schedule. When fertilizing, you might not get immediate results. It might take a full season or longer before the tree reacts.