It's not my plant, I saw a photo of it on instagram and I came here to see if it could be identified. I'm starting to think it's a bird of paradise too.

I'm still new to maintaining my houseplants...so don't take my advice for definitive truth. Yours looks similar to what mine does and here is what I've concluded is the likely issue: Improper soil drainage. Many users have noted that even their local nurseries tend to use soil mixtures that are 1 part peat, 1 part perlite or some variety of that. The soil really ought to be (per Al's suggestion) 5 parts pine bark fines, 1 part spagnum peat moss, 1-2 parts perlite with garden lime. The pine bark fines help aerate the soil and allow the roots to breathe. A good article on that can be read here. Maybe it's an issue with the roots as well? Or a mixture of the roots being overcrowded & drowned in water? When the leaves get curled on a monstera, it could be a sign of low humidity. Maybe try misting the leaves more or using a humidifier?

The emerging leaves are pale, telling me that it's not getting the bright indirect sunlight it needs. The soil mix looks fine, very similar to what I use, but it's not getting watered enough. These plants love water, they just don't like wet feet. If that makes any sense. With the soil mix that you're using, you can water it much more often. Mine stays outside for most of the year and I water it almost daily. Plus, I rarely fertilize it and it still grows like a weed. That's because it gets all of the bright, indirect sunlight that it wants. It doesn't matter how much fertilizer you "feed" a plant, those fertilizers aren't food, and they won't do any good if a plant isn't getting the sunlight it needs to photosynthesize. Plants manufacture their own food, and they can only do that through photosynthesis. As for the aerial roots, you won't really see many of those until the stems grow much longer. Just give your plant much brighter indirect sunlight and more frequent waterings, and it will take care of the rest itself. These plants are called monsters for a reason, HaHa... Also, don't bother misting. Monsteras love humidity, but will grow perfectly fine in the interiors of our homes. My place uses gas heat, which pretty much strips any moisture out of the air during the winter months, and it doesn't phase my monstera one bit.

Looks like over watering. That can happen when the soil doesn't drain fast enough so it retains too much water causing root rot. These plants are semi-epiphytes that usually grow up tree trunks. The roots run down the tree trunks and on the ground run through the leaf litter on the surface. In a humid environment the roots are constantly exposed to air and get moisture from the humidity. During heavy rain the water on them is highly oxygenated but drains almost instantly. When kept in soil care needs to be taken that water drains away from the roots fast and that there is air movement amongst them, ie. a very light, aerated soil.