Under watering will cause the leaves to shrivel and become brown….sounds like that could be the problem. Also, might get an insecticide for plants just in case. Look up the plant on the internet. There should be care instructions there. I have a boat load of plants. Some are really big. I usually water them all once a week during the summer, and water them until it runs out the bottom. In winter I water maybe every other week. I’ve also found that the more I fuss over my plants the more problems I have with them!