The Japanese Boxwood has yellowing leaves and dropping. Reported and pruned three weeks ago. It's been in the shade for two of the three weeks. It's been only in partial sun (3 hours per day) this past week. The trees are in an area that now only gets 3 hours of direct sunlight. I expect this to be the case until spring. I'm in Florida and the temps are in the high 50's to mid 80's. I'm watering every other day sometimes two days goes by before i water.

Suppose you did something like repotting and or overwatering. It is outside I hope?

Prunned and potted three weeks ago. From nursery pot to bonsai pot. Water every 2-3 days

Are you watering when it needs it? Or are you just doing it every three days regardless?

Every two to three days regardless. However, it's in very very fast draining mix. The mix seems to be dry before I water.