Hello!
I'm a begginer and since July I have a Chinese Privet, my first Bonsai.
Now in the winter (Lisbon, Portugal) when my tree was in my room by the window (indoors), some brown spots and fungus started to appear on the leaves so I placed the bonsai outside for a better air circulation and I also sprayed a fungicide once a week. The diseased was treated, but after a week or so the leaves started to fell.
I don't know what to do. I put the tree inside again until I solve this problem and because of the strong winds and storms now felt in Southern Europe. I only water when the soil is slightly dry.
Could you please help me? What I am doing wrong?

1) How do I treat the leaf fall?
2) Should I cut the now empty branches where the leaves fell?
3) Can I grow a Chinese Privet Bonsai indoors?

Sorry for possible English mistakes
Thanks in advance and happy holidays to all of you

Eu deixaria a plantinha fora, mas protegida dos ventos.
Leave it outdoors, protect from the winds.
Fungus will reappear if there is no air circulation.