This is a side note, but my personal bias is pressing heavily on me, so I have to say it... I would seriously look into a better nutrient for what you're growing. 3 part formulas for peppers are unnecessarily expensive, tedious, and wasteful. Regardless of what the "other" customers at the hydro shop do, there is absolutely, positively, no need to "Veg" and "bloom" a pepper plant. (it's actually ridiculous, in my opinion) There are great 1-part formulas that keep everything simple, and achieve the same result, with so much less hassle. OK, I said that part, let's go on to the next...
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I seem to remember somewhere in the forum, that somebody brought up this issue before. And that it affected certain Chinense varieties, in particular. In fact, I've seen it on my own plants. I would first look at every single environmental variable - no matter how small or insignificant - and see if anything in your grow room is acting differently upon that plant, in particular. Take your time, don't discount anything. Maybe even journal it. Not guaranteeing that you'll find something. But I've found that strategy helpful.