I get DMs from all over the world asking, "What's wrong with my plant?", and 99% of the time the answer is TOO MUCH WATER! It's too much water because there isn't enough light, or too much water because the days are short (still a light issue), or too much water because it's cold, or too much water because the pot is too big, or too much water because the soil is not fast drying enough...

•Learn when a pot is dry•
I love peace lilies to teach how dry a plant can go and recover (not all plants can do this). Get a peace lily, water well, feel the weight of the pot. Very heavy. Then let it sit days and days, maybe even a week or two, till the leaves start to turn down with a slight wilt. Leave it even longer. The leaves will eventually collapse and the soil is well and truly dried out. Feel the weight of the pot. That is a 100% dried-out pot. Water it now, and it should recover.

With my peace lily I wait for a slight wilt then water, I try to avoid the total collapse. Now, what has this got to do with pilea peperomioides? Pilea peperomioides like to dry out nearly completely between watering. I want you to learn the weight of a just watered pot, and the weight of a nearly 100% dry. I don't like to let my pilea peperomioides wilt too much, so get a peace lilly and practice weights.