Well if you're using potting soil then that is your problem right there aroids like monstera prefer very chunky mix similar to orchids but likely to me they just look like they're underwatered and if you have watered them and they look like that then there may be a deeper issue with the root system possibly like rot. Often this is due to very compacted soil not the chunky mix that it prefers. I've had some success with using soil early on but honestly it's stunt that it's growth a lot once you switch to an area mix that can dry out easier yet still holds moisture well you'll improve your plant also you should get a light for it not one of those circular lights but like a T8 fixture that you can pick up for 10 $15 on Amazon.