I have attached photo of plant that I have for about 7 or 8 years. It was replanted into a much bigger pot about 18 months ago, and since that, the leaves are getting brown patches and sometimes the full leaf goes brown and dies. It is not in direct sunlight. I water it (and feed it in summer) when the top of the soil feels dry. Is there anything I can do with it at this stage?
Give it more light, not too hot, perhaps an east or west-facing window, and just keep it barely moist and do not feed until you see some new growth.