We got this plant from someone else a year ago. It was doing fine until 3-4 months ago, when some branches just died (turned black).
It's winter now, but we keep about 19-20°C (66-68°F) inside. Sunlight is limited though at 58 degrees North latitude.
We've tried to give it more water, less water and fertilizer. It just seems to get worse.
What's the best way to treat this plant?