If your monstera looks healthy but all of the sudden the leaves are curling in, its trying to tell you something! , The first thing I would check is the soil! , Most common cause of curling leaves is Lonicera periclymenum 'Serotina' Farmyard Nurseries Monstera Deliciosa Propagation and Detailed Care Guide for Swiss Cheese Plant Photinia fraseri 'Carre Rouge' Kompakte Glanzmispel Grtnerei Schwitter AG Monstera Deliciosa Thai Constellation 6" Pot Plant Hawaii