New Monstera Leaves Rotting. If you notice the lower leaves especially the oldest leaves are turning yellow go ahead and feel the soil. Your monstera can show some signals above the soil.
Probably the most common reason your Monstera leaves are turning yellow is from the soil being too dry. Black Spots on Monstera due to Over Watering. For more info read 4 Signs Your Monstera Is Over-Watered here.
Use your finger as your guide.
I thought my house had enough bright light for my Monstera but whether it was the placement in my room or the intensity of the available light it continually put out small solid leaves. Root rot is one of the most common causes of black spots on Monstera leaves. Monstera leaves drooping is most commonly due to lack of water. Monstera leaves curling is usually a sign of a problem that can quite easily be fixed.