It does look like overwatering and potentially too little sunlight. My indoor Monsteras have grow lights for 12 hours, outdoor they do well under a patio with partial sun through the screens to give you an idea. They do well in heat and humidity, as long as the soil isn’t crispy. Less of an issue indoors. Definitely let it dry out between waterings, best of luck!
Are you thinking of a duvet, maybe?