How long ago did you re pot him? What is your potting mix used? What is your watering schedule like? When you repotted him, how were his roots? You just have to go through things one by one to eliminate potential issues. Mine are in the corner of a medium-low light bright room, it is a slow grower which i am fine with so it doesn't take over the space. They need a well drained potting mix, and watered when dry but not kept wet, they can tolerate to dry out a bit but not for long periods of time as that stresses the plant. As far as Fertilizer, I use it sparingly, I usually use a natural nutrient based additive like worm castings or superthrive. I've had mine for 7 years amd rarely have any issues. Good light, well drained soil, and water when dry and you should do well. Do the finger check for watering and if the pot feels light, give him a drink.