Can’t get flowers to bud on pepper plant (aji charapita)

I have tons of flowers on this thing, and it's been like this for months. It's big and healthy and gets lots of light. PH is around 6 and nutrients are good (MasterBlend 4-18-38). I'm using DWC in big Costco Totes. But for the life of me I can't get the flowers to turn into peppers. They just fall off.

I was reading it could be temperature issues, since aji charapita are from a tropical climate. At night it gets down to 18 or 19 Celsius (about 65 Fahrenheit). In the day it stays around 24 (75 Fahrenheit), but sometimes gets close to 30 (85) when I close the tent (it's in my office).

What's going on? Do I need a space heater? I have some banana peppers in the same environment that are producing big, happy peppers. Same with tomatoes.