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!
Can we see the rest of the plant? What does the soil look like? How much sun is it getting? Was it transplanted recently? As others have said Monsteras do like to dry out. Water just the soil once every week or so when soil feels dry, every two in slower seasons. Do not spray the leaves, make sure when you water you are giving it enough to encourage deep roots.
I didn’t think so either in my case, but my stomach lining didn’t agree. I ended up doing a blood test through Everlywell and found out I’m allergic to a hell of a lot of things. I hope your issues clear up soon 💗
Something similar to this happened to me because of food allergies (undiagnosed wheat and milk casein, gastroenteritis for over a week). Can you try switching to plant based ensure?
Plants that get dramatic between waterings work well with self watering pots. I have my fittonia in them and there’s a big difference between them and normal pots. I would suggest them for plants that don’t like fully drying out between waterings.
I would give my indoor plants outdoor time, until my Birkin came back with a weird earwig looking bug hanging out in the soil 😂 I know it’s silly but he stays outside now.