Looks like a nymph (immature/wingless) of an assassin bug. That's good since assassin bugs are considered beneficial, feeding on many insect pests. I have them all over my peppers, and that's fine with me. I wouldn;t handle the adults though, since they can 'sting'. But only if you pick them up. They use their mouthparts to impale other bugs and inject toxins.

The leaves are wet because it rained today! :) I water the plants through a tube and I don't get the leaves wet. They are planted in Al's mix. They get sun from about 10am onwards through the screen. The screen probably stops air circulation a bit so I've moved the plants out. I think it's just bad luck. Most of the plants are fine and I'll give them all a blast of fungicide when the rain stops.

That is not a very good picture. Maybe take it outside in the sun to photo next time. But, no, it doesn't appear to be nute burn. nute burn typically looks like the edge of the leafy is drying up. turns dark brown and gets crumbly.

I had this same problem awhile back, which many fellow members chimed in on. Although we didn't really find a solution or the cause, for that matter, there were a lot of good ideas. For what it's worth, if I recall correctly, I always have at least one or a few pepper plants (of any variety, no consistency in variety) that does this every year for reasons I've never been able to pin down. While I do tend to experiment with this or that, all of the plants use the same soil each year and many times, the exact same style/size of pot and/or ground, too. [Wrinkled Leaves Thread[(https://www.houzz.com/discussions/yearly-issue-with-only-a-couple-of-my-peppers-dsvw-vd~3279243)