Hello again!

As you remember my bonsai started thriving and giving new leaves, looking very happy. I got a soil moisture meter to check on the moisture daily. My bonsai has recently started to lose leaves again. What could I be doing wrong? Could it be fertilising it?

Chinese Elm is a Deciduous/Semi-deciduous, there's nothing you can do about loosing leaves on autumn but to wait for spring and see if the tree can take the winter...