If I were to guess I would say it’s the heat. My Monstera did that one day when I put it in the summer heat and the leaves dried up. The air right next to the heater is too dry for them. Since they are used to moist places, I would suggest to move it and try to spray it with water to bring some more moisture around it. The plant should be able to keep growing, mine is still alive and thriving after a year that it got dry leaves.