One more picture.

Way too much water and over-watering is the primary reason for peppers to drop their leaves. Peppers, even more than other seedlings, much prefer to dry out a great deal between watering. The soil in the pics looks drenched.

Dave

The first picture looks as if the leaves have been bitten off rather than dropped. Any bugs lurking under those trays?

I haven't seen any bugs, but I will keep and eye out.

I will cut back on the watering.

These peppers were started in root-riot cubes which hold quite a bit of water. Soak it up like a sponge.

Thank you.
Zach