Hello James 698, and welcome to the forum.
There is a lot of conflicting information about caring for this plant. For starters, I don't think it's an epiphyte.
Is that a self watering (semi-hydro) pot? Remember that those moisture meters are not very reliable, and the bottom soil will be almost constantly wet.
A friend gave me a pilea cutting about two years ago. It didn't do well at first, always a little droopy and chlorotic. I decided to change my care regime, see if it would do better.
I repotted in a ceramic pot with good drainage. I used a fast draining houseplant soil.
I started treating it like I do my Phalaenopsis orchids.
It's under a grow light, 16 hours out of 24.
Once a week I soak it in water with orchid food, for 20 minutes or so. Then drain well. While it's at the sink I occasionally rinse off the leaves. If I don't have time for the soak, I water well.
I let it dry out until the next week. The soil is almost completely dry in a week.
It greened up, started putting out pups, and is getting too tall for my space.
I've left the pups on so far. They help keep the main stem supported and straight. I'll be repotting and dividing soon. I plan to start over with one of the smaller pups in the same pot. I'll give away the rest.
It does still drop leaves from time to time. I just pull them off when they're loose. The new pups are filling in, and the mother plant is steadily growing upwards.
This has worked well for me. I suggest you experiment a bit, see what makes your plant happier. Maybe try it out of the self-watering pot, more light, lots of water and regular feeding.
