What's your general location?

Have you been paying attention to the watering regimen? Does the soil drain well in the location?

I'd suggest that you look for small caterpillars on your plant.

I had one of these plants some years ago. I had it outdoors for the summer and brought it in before winter. The leaves started to yellow and drop off. I started seeing tiny flying insects dead on the floor near plant. On examining the soil I found tiny white insect eggs. I almost lost all my inside plants. I used dish soap and water spray to all my plants along with removing each plant from dirt and dipping the roots in dish soap water making sure allmost all dirt is off roots.l washed the flower pots of all dirt and repotted all in fresh potting soil spraying all the plants thoroughly again 5-7 days later.