Issues with indoor pepper plants

First off, I’m a noob when it comes to growing peppers, so please take it easy on my if I’m doing things that are stupid.

I’m growing six pepper plants indoors: 2 ghost, 2 reaper, 2 habanero. As you can see in the pics, they’ve grown to a decent size, but I’m having some ongoing issues that I can’t seem to solve:

1. curling leaves. I think it’s especially prominent on the reapers. I’ve tried insecticidal soap over a couple of weeks, improving airflow, being careful with watering, but some of the new leaves are still coming in curly. Don’t know what to do
2. leaf and bud drop. Across a few of the plants, several buds have turned yellow and

fallen

1. off. Also some healthy looking leaves doing the same. Totally stumped on this one

Any advice is welcome.